A commonly misspelled word can't automatically become "correct", because there is always some etymology behind a word and it doesn't allow you to mess with it. "Ridiculous" is of Latin origins, for example.
Just use a dictionary or spell checker for spell checking. The google "did you mean?" is a fallback, not a true spell checker.
I wouldn't be so forgiving about bugs in GMail's dictionary though.
Just curious, any of you go look up how to spell 'misspell' just to make sure you didn't misspell it? ;-)
Very true. Gmail misses misspellings all the time. Often I have to fire up emacs to double check.