>>14
a "mother fucker" meant that he was A) taking advantage of poor and downtrodden people with no options, and B) incapable of seducing non-desperate women. Anyone with experience growing up in desperate poverty, or who saw his own parents humiliated by circumstances beyond his control, would probably consider that type of behavior to be degrading.
In the last sixty or so years, the term has entered the popular slang as a term of derision ("That guy is a real motherfucker, you know?"). More recently, it has been used as an indicator of extraordinary intensity, not necessarily in a derisive sense, but usually still carrying some implications of harshness ("I fell asleep out in my lawn chair, yesterday, and got a motherfucker of a sunburn.") or intimidating awesomeness ("That Marilyn, he's one baaaad motherfucker.").