Oh, I don't know, maybe correct punctuation and grammar show an eye for detail and willingness to get things right? Like wiring a panel correctly or putting all the fasteners back in a fairing. How do you separate where you are going to spend that attention to detail? Is near enough, good enough?
I certainly wouldn't employ someone who's job it is to communicate if their punctuation and grammar was garbage.
And I'm not having a crack at ya Wal old mate