The focus is on killing because we understand that the brain is the organ which generates sensation and presence. Plants completely lack the machinery to integrate information on the level of even a ringworm. Once you get to the size of the animals we commonly eat for food, there is an immense amount of complexity, much more similar to ourselves than different. The ethics of veganism if very coherent. The brain generates subjective experience, the feeling of being something. To deprive one of that experience is wrong- most people would report preferring to be than not. Of course, to your point about subordinates, vegans should also treat humans with respect. Actually, veganism provides a framework that tells us WHY we should treat other humans with respect- because they feel, just like I do. So, if we can practically avoid causing suffering to those with brains, as most people on this website can easily do, it is best to do so. Most plants worldwide are grown to feed to animals, by the way, so even if plants suffered, we should prefer a plant-based world which minimizes this suffering. this would also minimize the human exploitation in the food industry and reduce our reliance on the monoculture which broadly produces the bevy of animal feed grown to feed the insatiable global appetite for animal flesh. One more comment on your alpine animals comment- those animals were slaughtered for their flesh. Could you "humanely" kill a human selectively bred to grow to the size of an adult in two years? How would you do it? Would the average person be ok if you painlessly killed them after two years of roaming through the mountains? I don't think so.