I don't spend a lot of time editing my posts for spelling and punctuation. I'm guessing I average one or two errors per post. There is also no shortage of bad sentences - my common errors are run-on sentences, fragmented sentences, and the like.

That said, I'm careful to communicate in a way I'll be understood. This is so I don't waste my time - I want my position to be clear (unlike some) and out of consideration for the reader.

After 13 years or so of arguing on the internet, my experience has been that the accepted convention is minor errors are overlooked because they don't cause someone to have to work to figure out what the other is saying. Major problems get in the way of the discussion. If I have to read something three times to figure out what's on someone's mind...

The little tiff between two of our loveliest members brought a few things to mind. First, the OP's post was only a story, so I think the complaint about the grammar and usage was genuine. When there's a heated debate and my opponet(s) begin complaining about my minor spelling errors, that indicates they have no other way to defang my position and avoid being eaten alive. In the thread in question, there was no such motivation.

Second, in some of the responses I saw some troubling thought processes. While there may be something to be said about publically criticizing someone, the belief that a person has to be perfect before being in a position to call for higher standards is not constructive.

Third, the one who loses the most when they write in a way that is difficult or impossible to understand is the one who isn't understood.