Good for you, ancientgran.
I know that when I read these boards regularly, I pick up information about word usage/syntax/context - and with that, spelling - and nobody knows that they've educated me, they just have.
Pedants Corner is a board that I visit quite often as it's a great sounding board for language usage. Those posters there really do understand and celebrate language and there's not a hint of judgement. Anybody can go, ask questions about the knottier aspects of English language and there will be answers.
AIBU is a bit of a bunfighty place with such obviously inadequate and self-important posters who will impotently launch themselves - unasked - to correct other posters' SPaG.
If SPaG were of genuine concern then the tremendous educational resource that is Pedants Corner could possibly be replicated on AIBU (for enhanced traffic) with no disparagement or hurt feelings caused. Very much an unfavourable comparison between Verve Cliquot and... used engine oil.