I think this works for both sexes - but it's not about being a 'bad guy/girl'. I think it's just about not being a doormat. I know that hubby and his mates have all dumped girls in the past who never said 'no'. And likewise, I like a guy who will stand up to me if I expect too much. Standing up for yourself or placing boundaries doesn't make a person 'bad'
And a guy who is great in bed - and a bit kinky - is awesome. And the total opposite: I remember a guy who used to get straight out of bed and wash himself. Epic fail.