You can basically argue that every fighter in history underachieved. There's always an excuse for losses, bad perfomances and dips in form.

Hatton's out of ring activities is just another bog standard excuse when we're trying to find meaning in something. He could have spent his career living like a monk and still have lost against Floyd and Pac.

Everyone is different. He could booze and live "bad" and yet still have a great career. Some people embarrass themselves after drinking two pints of beer, others act perfectly sober after ten.

I doubt there's ever been a human that didn't wish they had a chance to do things different. It doesn't mean it would have been right though.