Because they think they are so smart while they are hiding behind the computer looking up words in a dictionary or check spelling on their computer.

i dont know, its annoying... sometimes people type fast, so who cares... people dont have a life so they have to act like a grammar teacher and correct every lil thing they see. as long you know what they are sayin i do see what the prob is..

It's honestly really annoying. lol When I can't tell where one sentence ends and another begins, that's bad. When I can't tell if you're making a statement or asking a question, that's bad. I don't care about most things. A lot of people can't spell. I did attend a private school until high school; gramma was pounded into our heads. I understand this is a casual place to make comments. If it was a business letter, and it was full of grammatical errors, I'd say something. However, I just need to be able to read what you're saying! lol