What is with the prudence brigade that has dominated the conversation lately. It is especially bizarre coming from the site that almost gave Saints Row the Third game of the year. Sex and violence sell and get people pumped up and excited. This is not new and it is not unique the games industry. From car shows, to movies, to soap commercials, attractive men and woman draw attention and get people to check out your product. There is a larger conversation about misogyny in our culture, but when it comes to selling with sex you will find prominent feminists on both sides of the debate.
But to the general point i think it is strange and a tad bit fascist to want there to be some sort of top down ban on booth babes. In my opinion it should be up to the developer/publisher and the product they are trying to sell. It would not make sense to advertise for Schindler's list with women in bikinis. Likewise, for games that are trying to be mature and tasteful like Beyond or Journey etc. it does not make sense to have booth babes (and they probably don't have them). On the other hand, games like Saints Row the Third, DMC, and God of War trade in sex and violence, and so of course they should try to sell with booth babes. My point is that it should be up to the developer/publisher and any critique should be leveled at the developer/publisher (not the ESA). For example, I agree that Nintendo chaining women to 3DSs is strange, awkward, and offensive given the product they are selling, but that is on Nintendo.
There is, of course, a line that can be crossed. Unfortunately it is not one that is easily articulated. The best the Supreme Court could do is say, "You know it when you see it." I agree that games should be pushing into more mature and tasteful territory, and I tend to prefer games that do. But there are many gamers (including myself when the mood strikes me) that like dumb adolescent vulgar and violent entertainment also. There is nothing wrong with that and it exists in all mediums from music to movies to books. Some developers are trying to make something adolescent, and using sex to sell the product makes sense to me. They should not pretend to be something they are not.
Finally, modeling is a legitimate profession and many of the women who model actually like their job. I know this anecdotally since my wife use to be a model (she is a lawyer now). She and many of her peers really enjoyed what they did including the crappier work like trade shows.