I know this is sort of pointless, but I think that this rating can be a little bit insulting sometimes. If you're not English/American, it can be hard to spell the words sometimes and having this rating can be hurtful. Having something you posted be rated 'bad spelling' can be demoralizing, especially if it was just a few typos.
No support, this should stay because it will help people who post know if they made a spelling mistake.
No support. If I spell something incorrectly, I would like to know that I did. I wouldn't be offended just because someone gave me a helpful rating.