I would prefer if people who critic films and filmmakers have some idea of what they are talking about.
I think it's fair to argue that by the time you're one of a handful of directors making an $80 million dollar movie you ought to be really, really damned good.
It's the producer who hired him's fault. OTOH some executive green lit a project that was so commercial that it could be made horribly and STILL make a profit.
So I say the studio exec gets a raise and the director doesn't get hired for the next one.
In fact, if I was a studio I'd never rate my directors on profits. Profits are largely the result of the concept and marketing chosen. Many brilliant movies don't make money.
I'd rate directors on viewer ratings.
So... say Terminator or Transformers is rated really poorly by the viewing public - I'd fire those directors despite the movies being profitable. Those movies were profitable because of the studio and in SPITE of the directors.
OTOH if a movie was 4 stars and didn't make money I'd fire the VP that approved such a crappy idea that even perfect execution couldn't save it. But I'd sure as hell keep that director happy if he kept making 4 star movies.
I'd say Cameron and Nolan are rightfully safe for the rest of their lives.