I have seen many native writers boasting over their 'native writer' status. In their ads and sales copies this is a prominent point they use to distinguish themselves from 'others'...but, is writing just about perfect grammar? What if someone has huge knowledge about his niche and shows passion while explaining intricate details? Then does it matters his grammar is flawed, even if you can understand him and learn immensely from reading his articles?
I have seen some great writers who write about finance, with not so perfect grammar. Yet, they are quite popular.
PS: I am not talking about those who write in completely broken English. I am talking about those writers who can communicate their points easily, even in imperfect English.