I cancelled my subscription since I received a notification that my browser is not supported. Perhaps I should have mentioned my issues with DRM as well, but this may have gone too far. One message is clear, too many messages are noise.
While there is overlap it definitely isn't 1:1 though. There are tons of ff non-linux users and tons of Linux non-ff users.
This isn't to detract from what you said, just add to it.