Treasure hunting's probably too annoying for him.
Treasure hunting can be a pain in the **bleep**, sometimes. Took me forever to unlock Flynn's M9 and Marlowe's Para 9. Nowadays I don't even use the M9 or the Para 9. All that work for nothing Eddy's AK took forever to unlock too, but that's one of my most used guns, these days.
It's also the only incentive I have.