Yes it is always a pot and kettle situation with the people that shout loudest on threads having their own issues with spelling and grammar.
The Laqueen name years back, is a case in point - always going on about others and has the most bizarre easily recognisable grammar and spelling errors. She continues to announce the arrival of each of her new usernames on here with her very distinct grammar and spelling errors. No I won't be telling you who she is so don't ask.
The reason I noticed her was precisely because of her propensity to criticise others and announce her superior writing etc.
In over 10 years I've not highlighted this to her or anyone else (until today), as secretly it's a little bit funny to continue to see such pompous behaviour.
It is a one-upmanship and will put posters that are less confident about their spelling joining in a thread, I certainly wouldn't accept my dc trying to make others feel bad about spelling/grammar.
Yes, we know it's important for effective communication, but we're not a school. I don't think text speak is the way to go obviously!
The reason it isn't the same as crap parking is that it is the only essence of a person we can see - they might actually be lying about their opinions - we won't ever really know.
However, as I mentioned above, the errors tend to stay with the person no matter what name change they use - so it is essentially part of who they are.
It's not school and it is rude to point this out. I'm not in favour of everyone winning at sports day etc, but people shouldn't be dissuaded from joining in conversation for fear of mocking. In the end, It's just another way of shutting down debate.
Bad parking can be dangerous etc bad spelling, not so much.
When we want to correct our own spellings and grammar, then yes correct our own errors in a following post, don't pick others up on it.
We can listen to what someone says and still say it's a pile of poop and sound like a dimwit if they can't see how wrong they are ie. lively debate and discussion - it's healthy and good to question everything.
Calling someone a dimwit because you've spotted an error in their spelling/grammar is not ok IMO. It is something they may not be able to change.