You're presently illustrating exactly why Stallman et al were such sticklers about "Free Software."
"Open Source" is nebulous. It reasonably works here, for better or worse.
Free software to me means GPL and associates, so if that is what Stallman was trying to be a stickler for - it worked.
Open source has a well understood meaning, including licenses like MIT and Apache - but not including MIT but only if you make less than $500million dollars, MIT unless you were born on a wednesday, etc.
>"Open Source" is nebulous
No it isn't it is well defined. The only people who find it "nebulous" are people who want the benefits without upholding the obligations.
https://opensource.org/definition-annotated