That's like saying 'Yeah, I like smart girls, but I prefer my future wife to be a bit dumber' or 'Hey, I love a beautiful woman, but I'd rather that my future wife look like she was beat with an ugly stick'
I don't know, maybe some guys are intimidated by sexual woman. Then they go for the reserved ones so they can whine and moan about the lack of sex and put the blame on her.
Sexually aggressive/adventurous women are great. I don't think they're dirty or slutty but healthy!