Why do hot women become Hugh Hefner's girlfriends instead of grabbing other rich men?

Why do hot women like Brande Roderick, Holly, Crystal Harris, Kimberley Conrad strip for Playboy and then have to sleep with ugly old limp guy like Hefner? These hot women could have grabbed other rich old men and not have to appear in public limelight with old pimps like Hefner. Or maybe these gals are willing to go thru that with Hefner cos they are hungry for the fame and limelight so maybe they are not just after money. Or maybe they have low self esteem and think that other rich men would not touch them with 10 foot pole.