Why do Fincher's projects stall? The man's movies always make money.
Not really. Benjamin Button and Zodiac both underperformed, so did TGWTDT. Not that I give a shit, but he commands pretty big budgets (TGWTDT had a 100m budget, Zodiac 70m, BB... like 150m I think), tons of creative control, and that's always going to be tough for studios to swallow.
Anyways, it's a bit much to say his projects always stall... he put out Zodiac, BB, TSN, and TGWTDT in a really compact period. Now he's working on House of Cards (directed the pilot... plus another episode I think). He's definitely been kept busy over the past few years, especially for a director who's shoots are longer than usual, and spends tons of time and money in post-production.
edit: and pain in the ass? His casts seems to like him.