Not trying to derail the whole thing here, but:
Whedon was also a Jerk and somewhat abusive to the viewers.
I don't usually believe in the cliché of an artist being a great artist BECAUSE of him being an asshole - usually it just means he's an asshole - but Whedon might be the one exception. Because he's not, like, a great filmmaker or acting coach or visionary or anything.
But his writing is crazy good emotional manipulation, giving the highest of highs, and then the worst of lows.
Then again - the worst I've heard about him was being a massive, massive dick, especially towards actors (actresses!) that disagreed with him. But nothing rapey, violent, exploitative, racist, me-too-ish, defrauding, or anything else that Hollywood is also full of.
Just, like, really harmful words. Which is also the one thing he is professionally known for.