Sex sells. Even subconsciously you're going to be attracted... and it gets arses on seats for them to then pimp it out.|
If a pretty girl offers you a go on the game you're more likely to say "yes please pretty lady" than "fuck you, skank".
And when you come away you're likely to remember Batman for the hottie dressed as Harley Quinn than the gimboid showing you the next call of mah mah mah mah clone.
I don't think it necessarily says anything about the publishers or customers. They're just trying to add some glamour to games and push them more out of the dweebs in a basement vibe. Everyone chill out. They do it because it's a job / they like it / whatever. If you can save some of the slavering so they don't feel creeped out all the time that's a bonus.
I'm a grumpy bastard.