I don't see why men go ga-ga over Heather Locklear, for instance.

Well, not all men. Some of us have much better taste. But I agree with your main point, of course. Not only is it surprising what movie/TV stars come to be considered sexy, it's also distressing how it often happens -- seemingly by fiat on the part of some arbiters of sexual taste, whereupon oodles of people start agreeing.