I am a terrible speller. I openly admit this to all my students.
As someone who is incredibly detailed and struggles with perfectionism, it stands to reason that I should be a good speller.
So, I blame it on the fact that I am a visual learner, and when learning spelling as a child I was always required to spell orally and listen to the words orally. I just can't do that. Gotta see it. I was probably someone that actually would have benefited from a written kill and drill approach to spelling or at least a more creative visual approach.
Speaking of . . . My bloggy friend Jimmiecreatively teaches spelling to her daughter. I love observing all the fun stuff they do . . . I wish I could have done that too. Another friend (this one IRL) has her son, a tactile learner, spell out words with his body letter by letter on the floor or spell the words by "writing" them with his finger in mounds of rice or salt on a tray. Fun stuff.
Back to the topic at hand . . . I also blame the fact that I can't spell on the fact that I can rely on spell checkers to help me. In fact, since I can "teach" Word to auto-correct my most commonly misspelled words things have only gotten worse. :)
But, some people like this (now) 103 year-old man blame the fact that I can't spell on the fact that English spelling is dumb.