I think there will be some negativity from people who were expecting a flashy superhero, AHnold-like action flick. But this plays more like a tragedy, the way it's intended.
Those not familiar with the Punisher may think this is just a gore-fest between two sadists, and by the end I could see why those people would react this way. But it isn't.
In the comics, Frank Castle is an ex-Marine (a Vietnam vet, but I won't quibble with that since it's been 30 years since the Punisher first appeared) whose wife and *two* children stumble onto a mob killing, who then shoot the Castles with Frank the only survivor. Did we need this to be a massacre at the Castle Family Reunion? I don't think so. I didn't see DC/Warner wipe out the entire Wayne clan for Bruce to be motivated to become Batman.
I always like it when John Travolta plays the heavy, and I think he did well with it. He didn't go all Green Goblin/Joker on it. Thomas Jane is excellent as the traumatized Castle, who now only finds satisfaction in "punishing" the evil in this world. Some said that he seems wooden, but it is like the comic, where Castle considers himself dead (and sometimes damned) inside and falls back on what he knows, being a soldier in a war. He's not doing the secret identity thing. He only wears that skull as a harbinger of death to his enemies. Will the sequel turn that t-shirt into almost-spandex? Who knows?
If you want to see the Punisher, watch this movie. If you want a feel-good-or-at-least-ok superhero/comic-book movie, see "Hellboy." (I liked that one, too.)