I am a huge advocate of dropping online grammar.
If there is one thing I hate it's a grammar Nazi. To me if you're in a debate and someone corrects your punctuation, spelling, or word usage it really means they have nothing left. When someone makes any of the pre stated flubs towards me and my own common sense can't figure out what they mean I simply ask "what did you mean" or try my best and hope they politely correct me by correcting themselves.
You're online, you're typing as fast as humanly possible to get your point across, and usually dealing with several debates at a time so proper engrish is not usually my top priority. Just figure it out.
Even when I read online articles, there is something less I expect from them than the written paper word.
I see people on sites correct the author of an article as if to boost their own self esteem and when I ask why their big repsonse is "well their payed to write, they should do it right!"
Well get a job writing yourself then. Same premise, these people are writing several articles at a time sometimes and if that little red line doesn't say "hey stupid" they probably didn't even notice a mistake was made.
I will say is it disappointing to know we have become so reliant on spell checks, sure, but in the end the internet is not to be considered the ocean of the most intelligent fish. I would say 90% of users are based off social networks and youtube channels so really expect great things in the written world, but online can people just loosen up a bit?