Or if it's available and no one wants or needs them. I look for the alternatives. I don't think they should be domesticatedly enslaved to die just because they taste good, and their skin are fashionable to wear. Yes, plants are alive. It could be possible, just very difficult, and much life killed in the process to sustain life only eating meat.
Plants are different.
They're further of the chain of life. If there were just minerals I could eat and survive, I'm sure I'd just eat those. Plant are beautiful, almost all life on Earth couldn't exist without them. It's all a matter of degree, just like some scientist quoted. It would be nice, but I would not force or enforce it.