You should stand up for your ideals, but dying on the hill of what you call your ideals is actually getting in the way of that.

Because instead of making the point "this license isn't as permissive as it could/should be" (easy to understand), instead the point being made is "this isn't real open source", which comes across to most people as just some weird gate-keeping / No True Scotsman kinda thing.

"No True Scotsman" is about specifically about changing the rules to exclude a new example you don't want to permit. The rules haven't changed, and the attempts to violate the requirements aren't new. Proprietary licenses continue to be proprietary. Open Source continues to not allow restrictions on commercial use.

no, “No True Scotsman” is just about people not categories like open source