They created the term and, from what I remember, it would be a registered trademark if not for a whim of the trademark office deciding it was just a little too generic for them to feel comfortable granting a trademark registration for.
(“Creative Commons” wasn’t too generic.)
I believe it should be a standard term and, even if you disagree, a great deal of the term’s value comes from being basically identical to the definition of Free Software as defined by the FSF’s Four Software Freedoms and Debian Linux’s Debian Free Software Guidelines, except couched in more apolitical language, less confusable with “free as in price”, that companies can feel comfortable with.
Freedom 0 of the Four Software Freedoms is “The freedom to run the program for any purpose.” and point 6 of the DFSG is “No discrimination against fields of endeavor, like commercial use.”
Aside from that, culturally, it’s de facto standardized to be what’s laid out in the OSD and if you try to undermine its meaning like that, you’re just setting yourself up to be seen as a bad-faith actor who’s trying to cheat the system… similar to Microsoft’s “Shared Source” initiative.
(Or like the extreme feminists who get upset when their spin-doctoring of “feminism” backfires and people decide “I guess I was mistaken about being a feminist” and go looking for new words like “egalitarian” rather following along with the shifting definition of the word they originally chose.)
Fundamentally, the principles that were laid out are intended to allow software to behave like mathematics. You don’t get to use the pythagorean theorem for free normally, but have to pay a license fee if you decide to use it for NFT purposes.
If the OSI were to change the OSD to allow restrictions like that, it’s very likely that people would reject the changed version, declare the OSI to have become infiltrated by corporate influences, and start referring to the current version of the OSD (Version 1.9, last modified, 2007-03-22) as the authoritative definition of what “open source” is.