The game led to pretty much each one of those developers able to start their own studios and create whatever they wanted, or join whatever team in the future they wanted. I would think gratitude for Carmack's vision would be warranted.
I think about my own beginnings, working for a startup telecommunications company, which eventually folded, but the jobs that came after I probably wouldn't have landed without that initial grueling experience. Grateful for it all!
Sandy Petersen, who worked on Quake at id Software, says the game's development broke the team spiritually and triggered a mass exodus. John Carmack publicly responded, admitted his mistakes, and ended with "Sorry, Sandy."