I don't understand the position because it doesn't make logical sense unless you're doublethinking.
First of all, you have to ignore the fact that plants, too, are alive, and eating them therefore requires killing them.
(You seem to place particular importance on the will; but I hope you won't come back and tell me it's perfectly fine to slaughter coma patients right and left.)
A person who was (is) in a coma, had the capability at one point to make a decision. In fact, it is common practice for being to leave behind "living wills" that might state if they are in a coma without chance of coming out, they want the plug pulled. They also have the right to leave a living will to say they want to be kept alive as long as possible, just in case. So yes, will matters, even for Coma patients. This is apparent in the legal battles that often make the news when something like this happens and people have not left a legal document that specifies what they would have wanted.
Second of all, you have to ignore the fact that, unless you grow all your own plants in a hermetically sealed bubble, fruits and vegetables end up killing animals, too.
There is a moral difference between wholesale slaughtering of animals and trying the best you can do within a given system to minimize what you see as a problem. Seeking to reduce a problem that you can not eliminate is as reasonable choice. You are trying to make it a black and white issue by essentially saying that "well, you're going to kill some anyway, so what does it matter?" This excludes any gray area.
Third of all, you have to ignore the fact that suffering is not a required part of the idea of eating meat. It might be part of today's meat industry. But that does not make meat-eating in general an immoral issue, any more than, say, paying taxes is immoral because currently your money goes to supporting a war.
Well, we are talking about today's meat industry, aren't we? In some hypothetical future meat industry in which suffering has been eliminated, I will take that into account. I don't think those two things are quite the same. Tax money doesn't go exclusively to war, it can go to other things you might find valuable, like medicare and other socially beneficial programs.
Fourth of all, you have to ignore the fact that your life, your very existence on this earth, is by necessity carved out of everything else here, and causes death and suffering every day of every year, literally from your cradle to your grave. You can change the form but not the amount. Either accept it or kill yourself.
Again, you've made it into a black and white issue. There are shades of gray. It is reasonable to minimize one's negative impact even though it may not be able to totally eliminate, it. You claim that you can change the form, but not the amount. That is a pretty extraordinary claim, and have a feeling its pure rhetoric.
In summary, if you actually believe that killing and causing suffering in any living organism is wrong, suicide is the only option left to you, and to claim that vegetarianism is an acceptable substitute is ludicrous. It's a cop-out. And either you know it and you're being hypocritical, or you don't, and you're doublethinking.
Its not a substitute, like I said, its about minimization, not elimination. If its hypocritical to realize its impossible to totally prevent all suffering that happens as a result of my existence, but to try to minimize it, then fine, call me hypocritical, but I don't think it is by any definition of the word I am familiar with.