The trouble is that none of us knows what is going on in other posters' lives.
There was a time not so long ago that I resisted posting on MN because my mental health was so horrifically bad. Looking back, I needed support. I couldn't talk to anyone in RL. I was a shell. I couldn't even bring myself to respond to threads, let alone start them. With hindsight, I needed some support in any form more than ever.
Had I had the courage to post, and had I received reactions similar to those being discussed, I probably wouldn't be here. It was a bit touch and go as it was.
So when I see posters being pulled apart for spelling errors, or grammatical mistakes, or post structure, like Belinda, I die a little bit inside. Because it's not just commenting on the ability (or lack thereof) of the poster to post at what is deemed to be an acceptable level, but posters can actually be deeply hurt by such criticism.
Now, I'm not saying that we all need to be careful about what we post because it might adversely affect the professionally offended, but perhaps we should all just stop and think before posting something that could potentially be inflammatory.