everyones turning into zombies , its the end of civilization , and the local populace are ENJOYING , killing and torturing their friends and neighbours , really? *beep* stupid ending , yes i'd really get off on burning my friends n neighbours in a massive funeral pyre , pass me another beer .....
That's the point really. The human condition is the real horror of the story...more horrible than the dead returning to life.
First, with the 'survivors' inability to get along with each other long enough to form a plan of escape, which, we learned later, they could've done quite easily, but egos prevented it.
Second, the rednecks outlook of "this is fun", and their reaction by turning the situation into a game/celebration.
And yet it's the rednecks who are saving the country by doing this, it's not the government, it's not the army, it's the hillbillies that are saving humanity, the ones who everybody thinks would be too stupid to figure out what to do.
I think that there's a quite clear allusion to southern racism. The zombies hanging in the trees, the "old" photo at the end with the rednecks burning the corpses... It all seems like a KKK reunion.
It all comes down to Barbara's statement "They're us. We're them and they're us". Compare that one to Peter's monologue in 'Dawn of the Dead' (1978). Romero explores the most hideous qualities in humans. Aren't we just as driven by circumstance and inner nature to get on and make sense as the zombies are? Do they serve as a mirror to unbalanced desire?
I'm not saying I flatout agree. But you'll encounter this theme in all the major Romero films, aswell. I hope you've had a chance to watch his original trilogy (Night, Dawn, Day). This 1990 remake explores the redneck scenes in the beginning of 'Dawn' pretty well, which in turn portray a fleshed-out continuation of the trigger-happy militia formed in the original 'Night'.