Knowing grammar and spelling for common words is one thing. Going out of your way to know the spelling of obscure words just doesn't seem to have a purpose.
I guess I would rather learn about things in context than just memorize lists of words cause they're hard to spell.
SD
You won't catch me arguing the utility of knowing how to spell "antidisestablishmentarianism," 'cause frankly ain't none.
But I can see how it'd be handy to know the difference between "discreet" and "discrete" or "accelerate" and "exhilarate," and why one doesn't use non-words like "orientate" or "coronate."