I read somewhere that this generation is so different that it's basically an entirely new dialect of the English language, at least that's what I think I heard.
But like the others have said, every generation seems to have their own slang words. I'm sure 40 years ago, if you said "Hey" instead of, "Hello, Ma'am," or "Hello, how do you do, sir?" then there would have been people who had a major problem, just like their are people today who have a problem with "Yo, whaddup?"
If you don't like the slang that is used these days, then don't use it. But you can't force others to speak the way you'd like them too, unfortunately.