the OP refers to veganism
check this out:
wikipedia about veganism
in short, those people see animals as creatures who are not to be eaten etc.
which is IMHO nonsense, cause we were part of the food-chain since aeons.
An interesting interpretation about this is:
if its not allowed to eat other creatures, why is it then that vegetables and plants are not in the list ?
these are creatures (of some sort) too, but they just live on a totally different timescale.
A timescale so slow, they do not even recognize other lifeforms like us, or animals.
if you put the timescale into account its obvious that they even communicate with each other.
so vegans .. imho .. people who limit their horizon to the timescale they live in, and thats it.