Why do some on the forum complain so much about other people's (spelling, grammatical) mistakes?

What exactly do they hope to "learn" from their 'questions'? What is it they are looking to 'gain' (what knowledge??)? Are they just looking for a way to 'vent'? Are they looking for 'answers' to corroborate their own personal beliefs that other 'people' as they refer to them as, are just not as 'intelligent' as they seem to think they are?