Earlier quoted context omitted.
The point of insisting what "open source" means is that we want to ensure the freedoms that open source guarantees. If we don't insist on this definition people will start pushing licenses that forbid commercial use and other things, as this license forbids, and we'll embrace it because we think "ah, open source!" And yes, when you coin a term, you also get to say what that term means. That's the whole point of coini…
You're arguing about linguistic prescriptivism vs. descriptivism. Is the definition of the term what the coiner says, or is it how it is commonly understood? A lot of people are going to disagree with you if you claim that prescriptivism is somehow more correct.
We have a precise, technical definition of open source precisely so we can judge when a license satisfies the legal freedoms that open source demands.