I'm not sure how old everyone on this board is, but my guess its average is "45"(?). I see your point, but you have to keep in mind that the way "kids" write things on twitter, and FB for that matter, is usually shorthand slang. That doesn't mean they can't read or write above a 3rd grade level lol its just that for purposes of social media that is the "accepted" norm.
I'm fairly certain he doesn't do that, or any "kid" for that matter, on anything that has to be turned in for a grade.
As an anecdote, I have a friend that graduated cum laude from UM, did follow up Masters at USF and is an a professional field of work and if you saw his social media profile you might think the same of him and he is 24.