Romero is a strange figure. Why wasn't he able to really make it after id? From Daikatana to Empire of Sin, everything was a flop, more or less. Who is John Romero?
He is a good game designer who invented some of the common tropes of FPS. After Quake and Doom he tried things that were sometimes too ambitious or just didn't work out. First of all, most game designers don't have as much success as he had after Id. Second, how are you going to follow up games as successful as Doom. Also don't forget Wolfenstein, Hexen.. (Full disclosure: I met him once and he was nice.)
He does seem cool as an older, chill guy now that he doesn't have to live with the pressures of being a hit parade.