My guess is that he's posting this same remark on ALL the articles he can find. The idea being that if he can establish "good-will" with a writer in need of editing, they will later hire him to do the same thing. It's the sort of stupid message I get all the time on Linked In, by people pretending to understand my business and how it can be improved, when I don't actually have a business. I did, but that was years ago, and I'm still in some business-owner groups just because I'm too lazy to go to the effort of leaving. It's bad marketing, but it must be effective (or some guru tells them it's effective), because they keep doing it.