Painting is just real life!
Well, it isn't. Walking down the street naked isn't 'normal' in most cultures, but it's part of painting.
Some artists really really like painting women in full frontal positions… because they really just love having naked women around. That's quite a sweeping statement.
Of course not all subjects are approached with the same scrutiny. This doesn't follow on in any logical way from your assertion that artists would rather have big Barry from the corner shop round to model than a beautiful young woman.
Might an artist prefer the woman? Sure, I can accept that. Would they, though, if their only option was big Barry, approach their painting of him with the same scrutiny as if they were painting a beautiful young woman? I'd strongly suspect that yes they would. Because that's what painting is about.
People seem to be having problems with my comment about artists scrutinising/observing, specifically in that they seem to be conflating those two things with the concepts of noticing or preferring.
As an aside, and obviously anecdotally, the teacher of the life classes I used to model for would often despair that most of the people on the life model circuit were young, slim women. He desperately wanted more variety and was massively cheered if he found someone of a different age/gender/body type and size.