I will never mind a "Hey, you misspelled «X»". I can agree "Ha, he misspelled «Y», he's such a complete moron" is annoying/disruptive, but I don't think the answer to assholes is to stop caring about basic grammar rules. Incidentally, as an outsider I've never seen people being as careless/clueless with their language as British/American people are. A result of the education system or society, maybe.

I think it's mostly the number of common homophones and the speed at which most English speakers think and type that causes the problem. Add that to obscure language rules and you can end up with something that looks completely wrong, but isn't.

A great example is "red-head scarf"; what you read is "(read head) scarf" what it means is "red (head scarf)". Granted, it makes the wording unnecessarily complicated, but it's probably grammatically correct.

By calling yourself an outsider, I'm assuming that you don't speak British or American English? If so, you're not really in a good position to judge grammaticality.

Or possibly a result of the number of people using the language. Including those with only limited experience.

I was talking about native British and American speakers. Not to mention that most of the people I've been in contact with were (highly) educated.