I agree with Mamod, perfect analysis, just a couple of additions.
Correction: "they find them "attractive", which is another level of beauty that isn't simply exterior, their attraction comes from:
1. their looks , DUH !!
2. hours and hours of polishing, makeup, fake parts (u know what i mean xD)
3. the fact that most of them are unattainable, meaning that they'll never run into them in the street and start a convo, that's a part of their attraction.
4. and most importantly, ATTITUDE on the screen through directors and script writers who can make the stupidest of them a brilliant rocket scientist, and they would simply tap into various male desires through movies. and of course, not to forget managers and PR teams of celebes who are working 24/7 to show them as goddesses instead of everyday human beings.
PS: i have a perfect example in mind to get my point across but I'm not sure i'm allowed to write it down here, so i won't. ohh and btw, why do you think that most guys are attracted to either actresses or singers, and not for example MODELS !!! who are supposed to be even better looking !!! could it be because models are usually not given the chance to speak when they're competing ??