There are several IIN threads about older men dating younger girls. In the comment section I always see some people trying to "talk the girl out of it". I believe they are either of the following people who have a vested interest against it:
1. older women
2. younger guys
3. Parents of the younger girl
IIN to think that?
1. older women
2. younger guys
3. Parents of the younger girl
IIN to think that?

Also, I remember back to when I was a teen and how thoroughly grossed out I was when men older than about 30-ish would make passes at me. At the time, I wanted to scream at the to "fuck off" but I'd just get away from them quickly.
And I have a very close friend who has a teenage daughter and the thought of some creepy old guy trying to fuck her and justify it with some equally creepy excuse makes my blood boil.
So, I'm not any of the stereotypes that you have listed, but I still think it's raunchy and immoral for my own reasons.
This summer I saw a 34 year old woman flirting sexually with a 13 year old boy. Later, she apologized to the mother of the child (they are/were friends) and her excuse was that she was drunk. Personally, I think being drunk is not a good enough excuse. There really is no acceptable excuse for it though. She, being the adult, should be able to control herself a little more.
Although, I could see where it could get creepy. Like with what Squirrel-Whisperer said. But if you're of legal age and you like them and they like you, I don't see what the problem is.
Also, I wouldn't go out with the sort of guy who'd prey on very young women.