Cannot see any benefit to it, but some problems I can see. I would much rather see what country they are from, since that could have a big bearing on what their post really means, and to how they perceive things in general. But I know that many countries are reprsented by so few, that it would likely give away their identity in a lot of cases.
I don't think anyone should be posting as anonymous. When you create a account your already anonymous. Unless you put your own picture. You can make up anything you want. to also post anonymous is redundant and just stupid. but if they are going to let them do it anyway, what is the point of seeing more info. As a rule I will NEVER give MHO to a anonymous person. Even if that is the only people that replied.