Some men may prefer to look at a blonde or pick one out in a crowd first because he has told himself that he "likes" blondes.
I've heard so many stories of people marrying someone who looked nothing like what they claimed their physical type was.
What I believe to be the truth is this: at least in America, there is a stigma placed on blondes ~ they just want to have fun, they are ditsy, they are gullible, they are easy, they like having multiple sex partners...... and on it goes.
So an immature man just looking for a great time would be attracted to the association of what a blonde is supposed to be like due to these stereotypes. It actually has nothing to do with her hair color & everything to do with him picking out the easiest target to get his immediate and "no strings attached" needs met.
It's sad really.