Lots of points of view, and really funny posts here. However, as Winston Churchill said concerning Calvin Coolidge's comment on the British war debts from WWI ("They hired the money, didn't they?"), "That is true, but not exhaustive."
We don't communicate with random collections of letters, or by ESP, we communicate with language. If one's language is full of errors, it's perfectly natural to conclude that that person's thought is probably flawed, too.
I would submit that there is a tendency to discount the comments of any person who routinely submits error-filled posts. At the risk of inviting snide comments or being considered un-PC, "I resemble that remark."
I don't know anyone here personally. The only way someone who posts has to get their thoughts across to me is by writing as well as they can, and taking care in the writing. I do not suggest that the writing needs to be complex or pretentious. But even simple English declarative sentences need not be full of mistakes in spelling, punctuation, and grammar. Further, I think that to do so indicates disrespect for one's audience.