Strangely enough as someone who has been trained in linguistics, I'm not turned off by bad spelling. I view it more as an evolution of the language.
Esp. when it comes to English, though, it really doesn't make sense to meter the evolution of the language by looking at *spelling*, considering spoken English, no matter how proper, has already evolved several hundred years beyond written English. In the 21st century, it doesn't really matter how modern/innovative your brand of English is: spelling rules will be a completely arbitrary set of rules that everybody has to learn. If somebody hasn't learned them, the implication for me is that said person just isn't that big on learning.
So there's a definite contrast here between non-standard grammatical constructions ("President Bush graciously invited Michelle and I."), non-standard use of words ("My head literally exploded."), and non-standard pronunciations ("'ello, my dear!") on the one hand, and non-standard spellings on the other. Grammar, vocabulary and pronunciation are always on the move, English spelling rules haven't budged in centuries.