>Am I just not understanding the entertainment industry? Or maybe has said person just written a number of excellent scripts that, for whatever reason, are just not picked up, but leaves a good impression on executives.

It's also possible that they were an uncredited writer on some stuff? Who gets credit as "writer" on movies can be really bizarre if a movie goes through multiple drafts. That could get you some respect from Hollywood insiders who know you helped but not get you a credit.

I'm not saying I think that's what happened (and probably wouldn't explain a whole career) but it's possible?