Diarrhea is only bad because we know what it's like to not have diarrhea (that sounds really friggin silly but it makes a point). There is a "good" alternative, you see what I'm saying? If there is no "good" alternative to anime as entertainment, how can anyone make that comparison?
basically it'll just boil down to people asking for anime to be perfect in their own personal ways, because if you're not using real alternatives, what other measure do you use? Perfection? If that's the case everything might as well be crap.
EDIT: of course, I'm not saying nothing is better than anime. I'm just saying there needs to be real things to compare something to to evaluate how good or bad it is.