I was pointing out his hyphenation to point out how it's something that nobody does, just like almost nobody writes e-mail anymore instead of email. The term seemed new at the time, so esr thought he needed special recommendations on how to use it.
And yes, I agree again with you, open source existed for a long time before OSI. It was and is called free software. All that OSI attempted to do was provide a more business-friendly synonym for free software, but their message seems to have gotten distorted, and people seem to think that open source is something different from free software. It was never meant to be different.