I have to be careful all day long in my spelling and grammer for work, as well as correcting others, and I'm not great at it. I'm not crazy about certain styles of writing on a casual board, but who cares...and who cares what I think!
On a casual board, I think it's rude to comment on other people's posting grammar and spelling. Many times I'm in a rush and I see I left out a word or mispelled because I had no time to spell check, and I cringe. I think it is better to be accepting of all posting styles rather than intimidate and discourage a reader from expressing themselves.
I remember a few years back close to when I came to JWN, a verrrrry famous JWD'er went on a little tirade about poor spelling, and "don't you want to do your best? Why not do your best!" In his own post he was called out for spelling errors. It discouraged me from posting for a while. Who needs to be criticized by a person who doesn't know or care about you when you are trying to heal from leaving cult and dealing with all the crap that comes with it?
Edited to correct spelling and grammar.