He's somewhat joking. In Revelations there are AI partners... BUT the thing is they're often away from you doing other stuff,and with that they never run out of ammo or lose health and you don't really have to take care of them. This reminds me of the first boss in Revelations when the chainsaw maniac was running after me and I ran upstairs to get ammo, and Parker was just standing there shooting enemies and getting grabbed and pushing them off and he just didn't give a ****, but it was alright since I didn't have to deal with him.
There are about two moments in the game I can recall where you have to help your partners.
One section in the stage with Quint and Flinton or whatever where one of them gets shot down and you have to defend him from oncoming enemies, and another where Jill has to help Parker limp through the ship, which makes you move at a sluggish rate as you try to get to safety.