The Punisher gets used a lot because the character is very cheap. Because the character’s inspiration is from revenge thrillers – he predated the Death Wish and Rambo movies, but not the novels they were based on – Frank Castle is just a guy with a lot of guns who goes around killing people in familiar urban environments.
Which means you don’t need colorful costumes or special effects for super-powers, you don’t need elaborate sets to stand in for alien planets, you don’t even need particularly good acting, because the audience’s interest is in the gunplay. Which means you can get by with the quite modest budgets that action movies used to be associated with.
I’m not a fan of the character, personally. The danger of falling into some really reprehensible territory on race, guns, criminal justice, etc. is particularly intense, but even when writers avoid those traps, I find that the stories get very samey – Punisher goes up against bad guys, Punisher shoots bad guys, rinse and repeat – without the scope for innovation or whimsy that comes from the clever use of superpowers.
Bottom line, I don’t think there’s much there to a character whose core conceit could be undone by a single sentence.