I guess it sucks to be incompetent.
It's not incompetence per se, it's Valerie Jarrett.
He's got a thing for Jarrett?
Not a romantic thing (not as has been reported); she's seen as the Mama Bear, protecting and
advising him, limiting others' access, filtering what he hears and sees. Every Chief of Staff has had to put up with Jarrett running interference, consequently the rapid turnover. When Daley first came on board, Jarrett's influence either temporarily waned or she gave Daley room to stick his foot in it. Either way, as regards Daley, it's "next!"
Jarrett,
born in Iran, has been involved with Obama going back to Chicago; her family and Anne Dunham before that.
Remember the meme during GW's presidency that Rove was his brain? By some reports, in the case of Obama/Jarrett, it may be true.