Not being able to spell does not automatically make a person a dolt. Keep in mind problems like dyslexia, and just plain poor teachers at the crucial learning levels for spelling. There can be many other factors as well. For example, I am a "scientist", but have lived in another country for so long that my spelling in English has suffered from lack of use. I hold a Ph.D., but came from a school district that while not the worst, did not have a majority of the students who were even Jr. College-ready. Still, I know many bright people with great ideas who are not top spellers, some of whom I met in grad school.