Why do teenagers on Yahoo Answers seem like they're illiterate?

They write like they text and they look like idiots. It's not that I can't understand what they're saying, it's that what they're saying is retarded. Is it just a phase or are they going to grow up being stupid people, too? I'm sure all the answers will be mocking and lolz, etc., but trust me. If you can't write you are going to be serving people when you grow up.