It's like a chiropractor going around and practicing his craft on random people he thinks might benefit. Just because someone with suspect posture is out and about doesn't mean they're presenting themselves for aid and assistance. Pedants want to practice their study of grammar on other writers because they're driven to do so by Ego. All I want is a pat on my back for my dirty stories. If I wanted help with my grammar I'd read a book on it or get a serious editor to edit my text.