When they were asked to clarify what exactly was violating their ToS, they replied with the most standard bureaucratic non-answer, the kind you might receive from an auto-response email service, full of corporate-speak.
[0] https://www.mozilla.org/en-US/about/manifesto/
EDIT: According to this[1], Mozilla supposedly cares enough about this free speech, free platform issue to donate $100,000 to "a coordination platform used by activists across the political spectrum, to improve the security of their email service". Do you still believe it's a stretch to hold them to a much higher standard than a for-profit corporation? Note the "activists across the political spectrum" part in their own words.
[1] https://blog.mozilla.org/blog/2017/10/03/mozilla-awards-half...
The article lists an 8 step process and claims users would have to follow that on each restart of Firefox to enable the addon. I’m not sure if that’s true, as the guidelines I can see on other websites seem to suggest self hosting addons shouldn’t have that problem.
[0]: https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/Dis...