I think people here are taking OPs question a little bit to seriously and Kevin Smith is 100% a valid answer. The question was about someone you "liked" and don't "like" now. Not, who turned out to be a horrible person.
Kevin Smith hasn't done anything controversial and genuinely seems like a nice man enjoying life and good for him. But, artisticly his movies have fallen off considerably in my opinion and lack any effort/message. Personality wise he's also made a major shift. Previously being more thoughtful and critical of things to now kind of just gone full "happy stoner shill".
As someone who grew up in 90s New Jersey Kevin Smiths and his early work will always hold a special place in my heart but I'll probably never watch anything new he'll ever make the rest of my life.
I've gotten into arguments with friends about this, but decades ago I stayed home from work sick and watched his Netflix special about how he got kicked off a Southwest flight for being too fat. I was raised religious and have evolved my thoughts over the years, but his parents were in a audience, and he said some of the most crass shit I've ever heard. My parents would've washed my mouth out with soap if I said what he said. I understand overall he's very generous, but seeing his special left a bad taste in my mouth.