My idea has been for a while that Duke very clearly needs to earn back some respect. I'm fine if they don't want to fuck directly with his character, but they need to put him in a world that has moved on from his antics. He doesn't have money, his own casinos, and certainly no lady friends. Basically, it's like a Metroid game -- all his powers are gone, and he needs to go on a mission to reacquire those things.
How does he do it? By just being Duke, killing aliens, and saving the world, as usual -- but it all needs to be done from the perspective of someone who has something to prove. Duke is a narcissist who doesn't love anyone but himself and only kills to *get* something in return; so those chips need to be off the table before people can view him as a hero doing something actually selfless.
Maybe then, in 2016 and beyond, he'll earn the respect of the player controlling him.