Someone please explain fake Rosie O'Donnell to me

It is irrelevant to begin with and beaten into the ground with over use but, can someone please explain why the intended joke is with Fake Rosie being sex crazed and masturbation obsessed?

Its the same thing that happened with Fake George Takkei: didn't matter if someone gay or straight was on the phone, if it was sexual in nature, the dumb knock at the door would happen and they ruined Fake George forever.