10. This wasn't talking about marketing people or spokesmodels
The ad in question specifically lists the women (not any attractive men) who will be serving beer as a primary "perk" of the conference. That isn't hiring an incidentally attractive marketing person/spokesmodel for their promotional talents; it is setting up and promoting an event with specifically female (not male) commodification and subservience as a key element. And while this may be common, it is not uncontroversial. The "booth babes" phenomenon has been receiving a good deal of attention from people in the tech industry who are uncomfortable with it. To some degree, I think you're proving the point of the people who are sick of it; you say A) these conferences themselves are outdated and unnecessary; B) the spokesmodels are an ineffective gimmick; yet C) there is some compulsion for tech professionals, even those who would prefer not to, to attend these conferences--including female tech professionals. They cannot just avoid them without consequences to their careers. I'm not a model or a marketing person (though I have served beer on occasion); I don't feel required to put up with sexism on the job.