You could make moral arguments for and against the companies seeking these protections and even Mozilla itself.
Ultimately businesses will always ruthlessly try to make more money, and software will ruthlessly seek a more efficient user experience.
Often these objective clash. Spotify is the obvious example that seemed to offer a solution in the music space. But we have yet to discover such a solution in online publishing.
How about paying? That will let you do more, in less time, and won't require an extra browser plugin, which means that it will use even less resources than using a plugin to bypass the paywall.
That said, you're free to try to get around easy "protections", Mozilla is free to take down your methods for doing that.