Just as the purpose of any heel turn is to ensure wrestlers are booed, the purpose of any babyface one is to try and rally support behind them. This is a bit tougher, in theory, because fans don't always play along or cheer who promotions want them to. If handled poorly, rebellious chants or worse, total apathy, towards the designated new hero become ongoing concerns.
Often, the motivations behind heel turns are to blame for that.
This list stars wrestlers who have switched from baddie to goodie because they're big, fat hypocrites who don't like seeing others steal their personalities. Others were expected to garner sympathy by revealing that they just couldn't be bothered to work hard anymore, or 'cause they saw the light after getting embarrassed by legends. All of this sounds ridiculous, but those were genuine reasons behind face turns in WWE.
They're not even the best examples either. Other face turns came about thanks to sex addiction, B-movies, miscarriages, a love of the good ol' USA and even because wrestlers dared to get traded to another brand in some made-up draft.