Some of us have important things to do, while others rant about grammar critics on a running site. Whether anyone likes it or not, frequent spelling and grammar mistakes make the poster look lazy and uneducated, irrespective of grammar "trolls" highlighting mistakes.
I live in a non-English speaking country, and can be tolerant of mistakes made by non-native speakers, and also imperial variants.
Two obvious problems with bad grammar and spelling:
- Poor spelling and grammar gives an impression of poor education, whether right or wrong, which may undermine any desired authority to communicate a message meant to convey important or accurate information. If the speaker doesn't have time to say it right, why should a listener take the time to listen?
- The chance of miscommunication is increased, if the intended message is distorted with spelling and grammar mistakes. If some says "wejo wants to bean IP addresses", but meant "wejo wants to ban IP addresses", the meaning risks not being properly conveyed to everyone.
I can't imagine any proper scenario where something is so important to say, that it's not also important to say it right. Isn't that a lesson from "Bambi" -- if you can't say something right, ssshhh, say nothing.
I don't see how anyone can make a case that giving an impression of poor education, or miscommunicating a message in a public forum to a large audience, many of whom may not speak English as a first language, is appropriate.