In any other scenario in court they always talk about how the guy was a bad dude...
*Is that true?
I don't know how I feel about it- just makes me uneasy for the backlash.*
It isn't true. The rules of evidence generally prevent evidence about 'bad character', though there are exceptions to this. But the basic principle is that a defendant is tried on the facts of the instant case (and not on the basis of allegations/previous convictions).
However, rape is a very particular case, because defendants can (and do) in certain circumstances adduce evidence about the character of the complainant (in other words their sexual behaviour). Given this, there is an argument to be made I think in rape cases for 'equality of arms' if you like.