I agree , and the proof is Fincher actually being involved in lesser projects like Dragon Tattoo.
He should be doing whatever the hell he wants...and that doesn't look like the case.
And even Tarantino , i don't know if they would give him 200 million for whatever project he wrote.
Nolan right now (until he flops) is in that sort of rare occasion where he can do almost anything. Like Spielberg or Cameron. That's why i think he should really continue to do these big projects , because one day that door might shut. Until then , let him go crazy.