Ok, I'm not sure if you're talking about mtgmaster's posts before this page, and if you are, then I may be mistaken (as I've only read the first and this page), but I don't see he was bitching about anything. It does really look just like constructive criticsm; but I think you were offended by:
You'll probably keep adding them too and never be happy with a fully finished game.
And I think he probably just misphrased this with the use of the word 'You'll'. When people begin adding lots of systems into their game, however, this is what tends to happen, so I agree you shouldn't overcomplicate things (not saying you have though).
I agree the car is a tad unrealistic, but I wouldn't be bothered by it that much (and giving it guns could make it a possibly overpowered weapon).
The game looks great as it is and I especially like what you've done with the lighting. The only thing about the graphics I don't like is the zombies, as they look a little too human, with just a bit of blood and discolouration of the skin setting them apart from normal people. It'd also be more interesting to see a variety of different zombies, though I understand that's probably a little too time consuming.