I'll have to take issue with you here.
The problem here is one of communication. You've touched on parts of it. Yes, if you don't use some rudimentary skills at formatting, spelling and grammar, folks will not bother to read your message. Even if it contains much needed data or thought. There is certainly that.
But it goes further. It presents the person writing as an illiterate hack. Just the kind of thing that those unfamiliar with the gun culture expect to find - Flea-pickin' bath-needin' wife-beatin redneck. It perpetuates a stereotype that is most definitely not gun owners in general.
It hardly advances
"a virtual community dedicated to the discussion and advancement of responsible firearms ownership." Perception is everything and first impressions are perception.
Here at the Firing Line, we find this aspect, important. Accordingly, after much thought and debate (all behind the scenes, here), we changed the rules for the first time in many years. If you missed it,
this thread tells why we adopted this new rule.
We do not overly enforce this rule. We are not the grammar police or spelling cops. But we do like to insist that everyone present to the world our best face, as
responsible firearm owners. Some people took exception to this new rule and left us... shrug... It's a big world and there are thousands of forums available for those who do not care about such things as Perception and First Impressions.