In terms of series continuation, what would that have accomplished?
I think that once the Governor plot is over, it’ll be the last we see of Woodbury and its inhabitants. So (we can hope, Woodbury is getting old), Milton’s time is limited.
If I’m writing the show, what else do I need Milton to accomplish to move the ball forward? He’ll be gone soon anyway. Why not have the governor do the rational thing and off Milton? He obviously doesn’t have a problem with killing people.