Well known scholar and intellectual Mary Claire van Leunen has this to say about spelling, in her famous book A Handbook for Scholars:
From what I understand, spelling ability correlates with nothing--not with intelligence, not with verbal ability, not with age (after childhood), not with eye color, left-handedness, cyclothymia, blood type, structure boundedness, authoritarian impulses, sex, race, religion, national origin, or any other measure the testers can develop. Some people spell well, some people don't, and that's all there is to it. If by the time you're twleve or thirteen you don't spell well, you probably never will, and you should plan your life accordingly. I know what I'm talking about--I have already had to look up how to spell two words in this paragraph.
Moral of the story: it seems that those who loathe bad spellers (as I'm sometimes known to do) ought to be a little more sympathetic. We all have our weaknesses.