Proper grammar in real life situations like regular school work does matter,but on the internet where grammar doesnt matter shouldnt be taken that seriously.
I mean even if you see someone make a simple mistake like use the word "Your" instead of "You're". Just simply correct them,and possibly explain to them why if needed. Because if you decide to get pissy and insult them. It doesn't make you better than them in any way.
We shouldn't shun people for their mistake.No matter how little they are. Sort of like how little kids dont know what a gameboy is.You should tell them what a game-boy is.Rather than insult them for not knowing.