I guess I'm disagreeing that they're "basic misspellings" in the first place, or related to someone's reading experience. Informal spoken English is often different from written English, and some people Tweet closer to how they'd speak. That doesn't mean that the same people would write the same way if they were writing a book (they probably wouldn't use "yeah" in a book, either), or that a certain dialect of spoken English is "incorrect".

I think you're measuring something other than spelling here, closer to measuring prevalence of certain dialects. Especially in the "anyways" example: if there's something objectionable about that word, it's a usage objection, not a spelling objection. People really do say "anyways", and that would be the correct way of writing it if you accept that usage. Spelling it "enyways" or "annyways" or something would be an orthographic error, on the other hand.