So according to PETA, does that mean all the
bacterial life that humans live with in a symbiotic relationship are exploiting US and they should stop it? Lmao.
Bacteria don't have any consciousness or rationality, and therefore, have no obligation to act morally. Nor do any other animals, at least not to the extent that humans do. Arguably, animals like dogs do have some sense of morality and proper behavior, even to the extent of feeling and acting guilty when they do something they consider "wrong," though they might just be anticipating punishment.
But you'd never put an animal on trial and find them guilty of a crime, as such, although some primitive societies have in fact done that.
So only humans have moral or legal responsibilities. This is a consequence of the fact that humans have the capacity for reason and to understand laws and therefore, to be able to deserve punishment.
Also as a consequence of the unique status of sapient beings, we have preferences that society is obligated to respect, to some degree. That is, what we would call "rights." To the extent animals have rights, they have rights that derive from their capacity for suffering, via Bentham's utilitarian reasoning that unnecessary suffering is an evil. There is also corresponding reasoning that unnecessary cruelty toward animals has the effect of brutalizing humans to the point that we also, as a matter of course, treat each other more brutally.
This fundamental difference, though, between humans and animals are why the rights of humans are in a different class. We have no obligation to honor the preferences of animals, or even their lives, as a matter of course.
When the choice is made between human or animal welfare, we are obligated to treat our own species (and probably other sapient beings) preferentially. That thought experiment where you have the choice of flipping a switch and a train switches tracks to hit a box of kittens rather than a little old lady is never going to be a puzzling moral enigma. You flip the switch, no matter how cute the kittens are.
(Well, unless the human is Nick Bate or something, then you flip the switch to run him over a second time.)
The problem with the lolcow branch of veganism (yes I did not entirely forget which thread this is) is that they don't really have a coherent ethical philosophy derived from philosophical principles, but instead a set of beliefs that are basically a grab bag. This is why their arguments often amount to emotional gibberish.
This is also why you'll see some asshat preaching at you about veganism while wearing a leather jacket.
So the argument that humans can never instrumentalize other beings for our own benefit falls flat. Even a pure vegan eats crops grown on land that was cleared by essentially rendering it uninhabitable to any wild animals previously living there, killing innumerable rodents, rabbits and other small creatures. The moral dimension doesn't fade away simply because killing these animals doesn't involve eating them. Arguably, if their deaths are inevitable, it would actually be
more moral to find a way to consume their flesh.
Now, suppose it were possible to grow crops and eliminate the accidental, incidental killing of these small animals, but the cost of doing so made the resulting food so expensive that humans actually starved as a result. Would this be moral? Clearly not.
So the issue isn't that humans don't have the "right" to choose our own welfare over that of animals, but of where to draw the line, and what our responsibilities are. And we do have moral responsibilities in that regard, they just don't necessarily include all becoming vegans or fruitarian Jainists.
Where the lolcow aspect comes in is when people who really don't know any of the philosophy they're arguing about put themselves on a high horse and assume they're morally superior solely because they're vegans, even when they often do things just as destructive to the environment and other living creatures as any meat-eater.
Also, as a matter of trolling, while I do consider Peter Singer a serious ethical philosopher, he often takes trains of reasoning like this to conclusions that people find flabbergasting and horrifying, and they'll flip out.
(Sorry, if I get off on a tangent like this again I'll put it in Deep Thoughts.)