Dissenters is a commercial platform, Mozilla are simply under no obligation to promote it or give it a spotlight under addons.mozilla.org. Unless you can point to a similar addon from some alt-left site that they have approved, there's no reason to suspect that this was a political decision.

Firefox requires that extension files be signed by Mozilla if you want to install a .xpi file from a website. They don't have to be given a spotlight, but this effectively makes it impossible for anyone who doesn't know how to manually compile and install the extension to even use it.

No compilation necessary. You just download the addon source, flip on the "debug plugins" option, and point it at the manifest file.

Still a pain in the ass.

Mozilla continues to offer Dissenter the ability to sign their add-on and distribute it themselves. Look at the takedown notice, where they recommend this approach.

yes yes - this was completely apolitical. The conservative bent of the community banned was completely incidental, just like ALL other bans of conservative thought by San Francisco based companies. Firefox is just being an neutral arbiter - nothing to see here folks, go home and celebrate true freedom: the freedom of SV companies to systemically censor conservative speech with impunity