y'all likely don't know how much GamerGate-related stuff took a toll on him. women in the industry have told me very bluntly that Fish took serious heat by being one of the only men they knew in game development who actively replied to and combatted GG-related hate and targeting. you don't have to like the guy, but I promise you, he was more active in giving a shit about GG victims than waaaay too many people (myself included, sadly). exactly where that landed in the Fez-related timeline, I can't say, but I promise you it changed his tenor about participating in game development and discourse as we know it.
or, in my own words (not his), getting predominately angry and targeted responses to the work you do can make it easy to not want to do that work anymore. how much of that he "earned," I dunno, and maybe he needed to disconnect to do his own personal work on that front. but I think of Fish the way I think of Bill Watterson: someone whose work I hugely admired and whose personal relationship to fandom was fucking complicated. (if Bill Watterson had been active on Twitter, I imagine our view of Calvin & Hobbes would be VERY VERY different.)
and just like with Bill Watterson, I'd likely want to see/play/experience future projects if they ever happened...... and have also made my peace with what it means to let go of a favorite creator as a fan. sometimes we lose creators to death, to retirement, or to their creative well running dry. it all happens. life goes on.