I actually think this is kind of scary.
If I had grammar like this when I went to school, I would be considered illiterate in Norway and fall under the governments aid program. But it seems the OP is getting by fine in school, which leads me to believe that the educational system in the US (and worldwide for that matter) is failing to educate our children. As a father of two, this is deeply distressing. I know kids in my country are just as bad, and to be honest there is really no excuse for not being proficient in your own written language.
This has nothing to do with slang or abbreviations either, as the OP is suggesting in another thread. Im sorry man, but your english is really so horrible (this isnt intended as an attack, but an explanation) that I find it very difficult to read. I can deal with the occasional "u" instead of "you", thats not a problem. I use it too in informal chats, though I tend to steer clear of it in message boards.
But the complete lack of punctuation and the flimsy grasp on the English language I see in these posts distresses me a great deal.
Words matter. our entire civilisation is founded on the written word. If kids today no longer ascribe any worth to the art of writing, how on earth will we survive as a coherent civilisation?
If everyone spelled everything whichever way they pleased, in a few generations time no one would be able to understand anything anymore.
So this is a really important issue, wether people like it or not.