Philosophically, it fails as an Appeal to Ignorance. Practically, it fails for a few reasons. Many of the plants we consume don't need to be killed and have evolved to expect and depend on our consumption of them. Additionally, the animals we eat need to eat plants. So anyone with a genuine concern for the suffering of plants would immediately forego the consumption of animal products.
I concur however, that if one has a genuine concern for plant suffering then only ethical course of action is suicide.
Exactly, so if we kill the livestock and eat it, then less plants will suffer.
"...these are the cries of the carrots, for tomorrow is the harvest time, and for them, it is the apocalypse!"
Its not death that is the issue. It is pain and suffering.
This is the result of the special status accorded to humans. One side of it is that we are the only animals capable of moral reasoning and so we should abstain from eating meat even if other animals do it, because we are uniquely placed to understand the harm it causes. The other side of it is that we are justified by being special among all animals to treat animals in the way we do.
Both sides of the coin start from the belief that we are not like other animals. This is obviously a very anthropocentric view: we, ourselves, think we're special. Most likely, no other animal does.
If you are in fact twelve... well, stop it anyway.