This is merely my opinion. It may be violent, offensive, and raw, but Rage is not garbage or unpolished. Not to be rude but I loathe censorship and anyone who advocates censoring art, literature, or film doesn't appreciate freedom. IMO: to impede another's personal expression is a crime against human rights. I am just glad I live in a free society that protects the first amendment.
Anyway, to assume that King was glorifying the situation in Rage is like saying he is against clean air or promotes killer clowns that eats babies. I don't know the guy, but I seriously doubt he promotes gun violence, dirty water, child labor and if he does, so what, it is his opinion and doesn't affect anyone so get over it. As Americans we can think, feel, and express how we choose to. If the man wants to write a story about a fifty foot raver chick who rapes circus freaks before she coves them with spicy muster...then great...even if it does offend tall raver chicks.
Okay, that's my rant for the day.
It's interesting you say that, because Rage feels like King really got pissed and drunk one day (no offense to Mr. King whom I am a big fan off). It read like the ravings of someone who was wasted basically. Not art, not Literature...
But Under the Dome and The Stand were art, something about Rage felt like a raving, but that's just me.