In truth, they haven't for generations. Wrestling fans need more from their heroes than goody-two-shoes behaviour, innocence and a lineup of snarling heels waiting to be knocked down on pay-per-view. They need to identify with designated babyfaces personally, and there must be some semblance of viewer choice to justify why a given wrestler is in the face role.
WWE's history is checkered with examples that prove they struggle when it comes to booking the courageous baby. Perhaps the strength of Hulk Hogan's peerless run throughout the 1980s and early-'90s is to blame for that - 'Hulkamania' ran so wild, for so long, that Vince McMahon has been desperate to recapture his magic ever since.
The problem is that not everybody can be Hogan, and even his mighty "prayers and vitamins" chat wouldn't have worked in any other era. McMahon's scramble to find that next babyface success story has led to countless mistakes with other characters.
Some actually looked to be heading in the right direction before errant writing spoiled their potential and turned fans off...