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.
I enjoy it, too. But with the old HC treasure drop rate it was really hard to unlock the character guns. That was really my only problem with HC. Also, I think I might hop on UC3 later to try to unlock Chloe's Tau (it's the only treasure pistol I don't have). Then I'll only need to unlock Navarro's AK and Chloe's M9 and I'll have every treasure/special weapon, excluding the ND, PAX, E3 and Comic-Con ones.