No one is saying you are a leper, duendy.
All that is being pointed out is the observation that many of the "believers" in the pseudoscience forum are also atrocious spellers (or perhaps simply too lazy to look things up) and similarly they tend to have horrible grammatical and syntax errors.
You can't blame people for wondering about the correlation.
A lot of the threads I read (on the internet in general, but from pseudoscience "believers" in particular) read as if they were written by someone who simply does not have a firm grasp on the English language.
If English is the person-in-question's first language, and he or she seems to have such a difficult time with it, it seems fairly safe to assume he or she is either ignorant (un/under-educated) or not terribly bright.
This assumption could be incorrect (perhaps, like my brother, the person is just a horrible typist, and this betrays his real intelligence), but if all you have to base judgement of a person on is that person's words, is that assumption such a an off-base one to make?
I don't care what anyone thinks of me, as long as they base their judgements on accurate information.
I happen to love language (though I CERTAINLY make my share of errors) and try to reflect that in my communication. Even if I did not, however, knowing that the only thing that a person has to base judgement of me is my words, I will put forth the effort to do my part in portraying myself accurately.