[Marvel] Why do the other heroes allow the Punisher to keep killing people?

I've been reading a lot of Punisher lately, and I've noticed whenever he encounters a hero, they usually make mention of how they don't like nor condone what he does. But rarely do any of the capes try to actually stop him.

Guys like Captain America and Spider-Man don't like killing, so why don't they just stop him? It wouldn't take much for Iron Man to blast him from a distance, or for Doctor Strange to put a spell on him to subdue him for his prison sentence.