To the grammar-obsessed human snob who pooped his or her diaper about all the "wrong" ways people like to speak and spell:
Not everyone is a spelling bee champ. Get over it. It sounds like you were able to sort out the terrifying wrath of misspelled shipping labels that ruined your day. Try exercising some tolerance.
What is more concerning is that you don't seem to realize that slang is not indicative of stupidity or inferiority.
Slang serves as an "in speak" for subcultures, identifying individuals as part of a group- individuals who may exist as a minority in their culture. This gives people a sense of belonging, even if you don't approve.
You probably use words that were once slang, once considered obnoxious or even crude, without thinking about it. I like poor grammar. I like slang. It makes life interesting. Try it.