That makes quite a bit of sense. In some ways Batman stops where the Punisher begins.
I think that DD and Frank set each other off because they could be each other. In another life Frank could have been a street-level hero like DD and Matt is only a few steps from becoming like the Punisher.
I'm pro-death penalty because I can't justify some people remaining on earth. Some crimes are beyond forgiveness. I get what you're saying about the state but some people need to be voted off the island.