Surprised you have such morals when it comes to filmmakers or artists. I mean, so what if they are pieces of crap in their personal lives? Hell, I assume that most people in Hollywood are awful people. It doesn't make me enjoy their movies any less. John Lennon was a complete piece of garbage who beat women and abandoned his family, but I still love his music. I think Tarantino is very likely a major [expletive] and is a creepy lech toward his female leads, but I love his movies. Roman Polanski raped a child (which is quite a bit worse than being a drunk racist IMO) and has, in your words, made zero effort to fess up to what a horsefeathers person he is, yet I watch and love The Pianist and Chinatown. Would you have the same criteria you are applying to Gibson if Polanski came out with a new critically acclaimed film?
Maybe you would, but personally it doesn't bother me if artists are major douchebags.
I find it weird that people make the effort to separate the art from the artist in an age when information about the artist is so readily available. I find it very easy to avoid anything related to roman polanski and woody allen in particular, who are known child rapists. And I haven't had interest in a Gibson movie since I've been out of college. These are known horsefeathers people and they don't make anything close to amazing enough to put aside how bad they are.