You, my friend, are an unfortunate victim of Spell Check Syndrome. Symptoms include a false sense of well-being when one fails to see any squiggly lines under the text he just typed. :-)
I saw it right away and corrected it in a quick repost but this is such an active thread that it was already 4 more posts down.
But you’re right. Spell check doesn’t correct most usage mistakes. That is the posters responsibility. And here on FR we have no excuse since all posts are auto-previewed.