Who he is:
Frank Castle was a Marine who survived three tours in Vietnam only to see his picnicking family randomly gunned down by mobsters. He declared war on crime, beginning with that menace Spider-Man.
What spawned him:
A freaked-out 'Nam vet who can't distinguish friend from foe is a concept explored thoroughly in The Deer Hunter, Taxi Driver, Platoon and your neighbor's basement. Too slow, Hollywood! The Punisher started this wave of PTSD violence. The only troubled vet to debut earlier was the book version of Rambo, who was trying to live and let live.
But Vietnam's old news, baby! We're blowing up way less humid countries these days. That's bad news for the Punisher's relevancy. His character is tied into what that down and dirty war means to the national psyche (apart from the freedom rock), and the mistreatment of its veterans (quite entangled with the freedom rock).
How he survived:
Dude, he's the Punisher. Surviving is all he knows how to do. It's right there in his origin story when survival becomes his curse. Marvel's tried four times to kill him, and he just comes back more existential. At this point, he's a 60-something-year-old man who's been raised from the dead more times than Keith Richards.
Dave Wilkins / Marvel
And, frankly, looking better
Unlike everyone else on this list, he survived the trend by internalizing it. Marvel keeps Vietnam integral to his story, because hate prevents wrinkles. Comics Punisher is the victim of meaningless violence, and sees society as a lie built atop the truths of the jungle. He's a man in an unwinnable war against human nature. Movie Punisher, who sucks, is the target of a mob hit for being such a swell cop, while being hunted by the law for wasting the time of three great action stars.