Dammed with faint praise. Actually, I have rarely aspired to be cool, so maybe this is "good".
In a professional/academic environment, people will be judged for their written work (as well as everything else, of course). The basic issue in all this is you want people to pay attention to what you are saying in your writing (and take your information seriously), not how you wrote your information. Bad/sloppy writing is a distraction. Look how distracted people on this thread get when they see bad writing, they totally lose track of the message.
I found the students who wrote clearly also thought clearly, and the students who wrote sloppily tended to think sloppily. Editing is a great tool, but most people think they write everything perfectly the first time through and don't need to edit.
Let's face it, if someone writes something poorly on FB, it is not a huge issue. If someone writes badly in a scientific paper, or a grant application, or a CV, it can be a major problem.
And I hope I was clear, because I haven't had my coffee yet :-( Dangerous writing before coffee. But I did use the Preview button.
This is a thread full of people complaining about the way other people use grammar. No one here is cool. Sorry.
This is how I feel as well...but then I have met R@63 in real life and thought she was somewhat cool. I think I can resolve this conflict by forgiving her for participating in this thread because she was a university professor and comes by her grammatical arrogance somewhat honestly.
Not sure about the others though. :)