It turns out Marvel wanted Jay and Mark Duplass to direct a movie for them.
The Duplass brothers have worked with actors from Guardians of the Galaxy (John C. Reilly) and Ant-Man in the past (Judy Greer), but Spider-Man: Homecoming feels like it could be the mystery Marvel film in this case.
The Duplass brothers, on the other hand, might be the sort of filmmakers that are just better off playing in their own sandbox rather than someone’s else’s.
Of course, if the Duplasses ever change their minds, there’s nothing to stop them from signing on for a Phase 4 MCU movie, should Marvel come knocking again.