Personally a beautiful woman tastefully dressed is more of a turn on than the slutty look anyway.
I guess it's different because I pay for conferences out of my own pocket, but I'm not going to go to all the hassle and expense of attending an Expo to waste my time at a vendor booth which spends its marketing dollars on objectifying women. The women may be there of their own free will and the whole arrangement may be perfectly morally straight (for the sake of argument), but the vendor is clearly disrespecting its customers' intelligence, and that itself makes me feel uncomfortable and want to avoid their booth.
Each time I've experienced the 'booth babe' phenomenon, never once did any of them know what an ARP reply was or how many key exchanges TLS modes use. This isn't a matter of nerd-quiz, it's that talking to them serves no purpose for why I go to an expo.
While several I've encountered have been both nice and pretty, I never once imagined that I was going to scurry off to a corner to make out with one or that they might suddenly provide useful product information, so a polite smile, the briefest of small-talk to let them know that I value them as a human being, and a thank-you and I was on to the next booth to talk to a sales engineer. Did the booth-babe vendor have something useful to sell me? Maybe, but I only have so much time, and this wasn't why I was there. I don't care if the sales engineer has a spare tire and a scraggly mustache, because I'm not there to make out with him (or her) either.
That booth babes is a thing tells me a few things: 1) target customers don't get to talk to pretty women much unless they're being paid (Jesus people, try being kind and friendly for a change) 2) target customers are mostly there blowing their employers' budgets on a half-assed vacation and don't really care about the cost or value, and 3) they probably play the Lottery and go to strip clubs too, for all their investment is worth (but I guess they have nothing better to do).
There would be no booth babes if they didn't provide value, and that they do is an indictment of the crowd attending. RSA might be putting up a roadblock, but the industry only needs to look itself in the mirror if it wants to find someone to blame. Stop being creepy and get a girlfriend, people.