I really don't get the critical abuse this game sustained. Postal 2 is a direct descendant of such games as Blood, Redneck Rampage, Shadow Warrior, and Duke 3D. It is naturally violent and rather lacking in political correctness, but that simply makes for a enormously funny game, with a protagonist whose one-liners stand alongside the greats. It's a simple pleasure, for those whose enjoy simple, fun, over-the-top shooters. Bad points? A bit too short, I managed to beat the main game in 2 days.
Either way, I found this game incredibly entertaining, and I was initially on the fence about it, too.