I generally try to check mine. Mostly because it was beat into me during my many years of......er......uh...... higher education.
That being said, I moderate a few of the forums over on Greybeards forum and there are a few southern and canadian fellows who are quite creative in thier spelling. Always makes it interesting trying to decipher some of what they post.
I don't particularily like it when people text and use all the shortcuts, but when posting I think someone should do their best work (I have two 7yr olds, so this is one of their catch phrases.)
Nope, not at all been. Poor grammar is a poor measure of intelligence. People who publicly bother with someone else's grammar are elitist and insecure.