Perhaps the intellectuals of less wrong individually have decided that they don't see animal suffering as a bad thing, or eating meat as leading to animal suffering, or any other very normal reasons for not choosing to not eat meat.
I avoid eating meat because I prefer to get a higher percentage of my calories from carbohydrates in my diet than protein and fat. But when I'm working out, you can't get a better protein-to-fat ratio than you can in meat (nuts, grains, etc. all have at least a 1:2 protein:Fat ratio, lean meat is more like 9:1, and I don't like getting my dietary protein from supplements). Which is only to say there are reasons for eating meat (I guess I only addressed reason 2, but I've thought about reason 1, and reason 3 is initially unconvincing to me, although I should do more research about it).
It seems to me that you are surprised and/or upset by the fact that other rational people haven't come to the same rational conclusions as you. What you should rather be pointing out is that this is an actual discussion that rational people should be having, and such a discussion hasn't yet happened.