Okay fair enough. I definitely agree with PGI when he says that there should be extensive background checks done, you can't just hand a firearm to anybody.
At the end of the day the people of the USA want guns so that's how it's always going to be. I'm glad that guns aren't legal in Australia though, I never really feel threatened here.
That's pretty much the bottom line, I mean the actual statistics and stuff show that the current system is actually very good considering the assault/gun owner ratio (I agree on background checks), but the bottom line is - it's an American right to own a gun, and nothing would ever pass, ever, to stop the masses from owning them, which is really the answer to your "why are guns legal there still?" question.
Just finished my leftover Chinese food, so good.