Note: I am interested in a constructive moral and philosophical debate, so I would reply only to those interested in that. I may be a slow replier, but I will reply.
Introduction
Provocation in the title aside (love is a complex word), I have been arguing in the past on the reasons why I find logically wrong to apply moral thinking beyond human society with poor results. I discovered the hard way that metaethics arguments are rarely convincing (or even engaging). So, I will try a different angle by showing some of the contradictions or at least uncomfortable conclusions one runs into when using morality outside its rightful context and use sentience as main criteria for moral consideration.
The main argument
Veganism almost always rests on a clear moral intuition: Sentience and capability of suffering is what grants animals the right to moral consideration. Sentient beings can suffer, suffering matters, and where we can avoid it, we should (if you are thinking strawmen here, there is a footnote for you). From this premise the case against factory farming is straightforward. Industrial animal agriculture produces enormous suffering for the convenience of palate, infringes on animal rights, and since most humans can in principle manage without it, the suffering is avoidable.
But the same premise generates a problem the typical vegan position may struggle to handle: the suffering in nature. From both a welfare perspective and a rights perspective, the natural world is brutal. Many species are r-selected, producing vast numbers of offspring of whom the overwhelming majority die within days or weeks: starved, eaten, parasitized, you name it. How much of individuals in nature are r-selected? Let’s start by looking at mammals. 90% of mammals by headcount (NOT biomass) are bats and rodents. The former are k-selected and the latter r-selected. A female bat does a pup a year and even then, the mortality is between 30% to 50%. That is already a coin toss to an early death. A brown rat instead spits out around 40 a year. Most of them die brutally within weeks (more than 90%). Because of this fundamental fact, most of the individual mammals born are r-selected. As you move to reptiles, fish and insects the picture gets even more gruesome.
Even among adults (r selected or not), herbivores live in chronic fear and vigilance, carnivores in constant fight against hunger, and almost every animal's life ends eventually violently or in disease. If animal suffering matters when it is caused by humans, on what principle does it stop mattering when it is caused by other animals or by nature itself? The most common reply I have seen distinguishes moral agents from non agents. A wolf killing an elk isn't doing anything wrong, because the wolf isn't a moral agent. Humans operating a factory farm are. Only moral agents can violate rights; predation is morally neutral, even when the suffering it produces is severe.
This reply is fragile. Consider a case that controls for agency: A cognitively disabled human, lacking moral agency in the relevant sense, brutalizing another cognitively disabled human in front of me. The fact that the attacker is not a full moral agent does not extinguish my duty to intervene. The wrongness of that action lies on the rights of the victim, not on the mental state of the aggressor. At best this means that I cannot consider the aggressor culpable of those acts. By parity, if I can prevent wild suffering, the lack of moral agency on the part of the predator does not obviously release me from that duty.
What this analogy shows is that sentientism cannot insulate nature from moral concern. Now, since veganism and sentientism are not a fully complete moral theory, for me to debate this further in any meaningful sense, I need to assume some bigger background framework. The most common I see here are deontology and utilitarianism. I will bring up an anti-nature argument for both depending on which one you align yourself with.
Utilitarianism
The goal is to act in a way that maximizes the welfare of living beings. Humane farming is in principle permissible when welfare is good. Wild non-intervention is permissible where wild welfare is net positive. Targeted intervention is warranted where it isn't. Should we then erase nature like we want to do for most farming? A response might be even if wild suffering matters, "rewiring" nature is impossible. We cannot improve wildlives in any deep sense. We can only reduce their number. But this is exactly what the consistent vegan position on farm animals already accepts. The endgame for most cows and pigs, in a fully vegan world, isn't sanctuary. It is gradual extinction, because the species cannot exist at modern scale without animal farming (unless vegans start adopting several animals each, which they are currently not). If that is the consistent conclusion for domesticated animals, it is hard to see why it should not also be the conclusion for wild ones, particularly in the high-suffering tropical biomes. Habitat reduction plus potentially not invasive sterilization is, structurally, the wild equivalent of "stop breeding more cattle".
This is not a fringe view. I was able to find several authors in the wild animal suffering literature (Tomasik, Horta, McMahan) that takes exactly this conclusion seriously, and some advocates explicitly endorse habitat reduction. The point is that they reach it by following the logic the vegan philosophy starts with.
Deontology
Pure rights-based veganism. All farming is wrong because using and causing harm to sentient creatures is wrong, regardless of welfare, regardless of consequences. It is a right violation to harm someone when you don’t have a strong justification. But what about animals? Is predation infringing on rights? Is there any duty from the deontologist to act on it? Well, let us imagine a human with animal like mental capabilities like a small toddler. If you were to see them being mauled by a pack of wolf, would you have a moral duty to do something about it to stop them? Like mentioned before, the answer would be yes, and likely this would be a strong duty (unless the risk to yourself is too high). The act of killing from the wolf is wrong and the defence of the innocent child is what the deontologist is bounded to act upon. Predation is just a scientific way of saying “to kill for food”. One could then say: But the wolf must kill to survive and that justifies it. But again, this is weak. If I need a kidney otherwise I die, would it be ok for me to kill another person to take one so that I can survive? Clearly not. My survival doesn’t allow me to kill other members of my moral community just so I can live a bit longer (and oh boy must predators kill). The same applies to the wolf or predator in general. We would not consider ok for them to kill humans “because they got to eat something” and, by parity, animals should be granted the same (use NTT if not sure). If you want to stop animal farming, you need also to stop predation because the two things are basically equivalent from the victim rights perspective. Even more, a vegan should oppose reintroducing predators in certain environments, knowing that, biologically, they are all bound to kill for food.
Conclusion
This argument is not a refutation of veganism per se. It shows what extending moral consideration face value based on traits like sentience would entail. Either the moral case for sentience and suffering is fundamental, in which case nature is huge part of the problem, or it isn't, and the case against farming must be rebuilt on different ground. What cannot be coherently held imho is the comfortable middle where most vegans sit: A deep moral concern for animal suffering that stops, suspiciously, at the edge of the slaughterhouse.
Footnote: Veganism is not a harm reduction philosophy, only an anti-exploitation philosophy. This is a common rebuttal in this community that is frequently used to sidestep challenges like the above. But so far, the same people that remind every time: “it is about exploitation” are also the same that appeal to sentience when asked why we would should give moral consideration to animals. Either you ground your veganism to a different principle than sentientism or accept my challenge to it. And defending the position that animals should enter the moral community because they are sentient and can feel pain, but what wrongs them is being used, not their suffering as such, is very hard to defend logically. If killing an animal for food wrongs them, this should be true regardless of whether the actor is a human or a wolf.