does it actually matter that people don't all the grammar rules or how to spell things?
Does it matter if someone does not write with perfect grammar and spelling? Probably not.
However at some point you have drifted so far from normal conventions that you are no longer communicating effectively. You can make reasonable arguments about both prescriptivism and descriptivism but if your spelling and grammar are so bad that someone can't understand you then you're not a descriptivist, you're just wrong.
I have encountered this more often than I'd like in professional settings. I work in software development, a field where precision is important, so if I'm looking at your job application and it's full of basic language errors then I absolutely will judge you for that.
Does it matter if someone does not write with perfect grammar and spelling? Probably not.
However at some point you have drifted so far from normal conventions that you are no longer communicating effectively. You can make reasonable arguments about both prescriptivism and descriptivism but if your spelling and grammar are so bad that someone can't understand you then you're not a descriptivist, you're just wrong.
I have encountered this more often than I'd like in professional settings. I work in software development, a field where precision is important, so if I'm looking at your job application and it's full of basic language errors then I absolutely will judge you for that.