https://jolt.law.harvard.edu/digest/mozilla-announces-resign...
https://wiki.mozilla.org/Speaker_Series#Monday_Oct_1.2C_2018...
https://twitter.com/datasociety/status/1093227579723730946
I could go on forever with Mozilla's connections to organizations promoting and facilitating politically motivated censorship.
Because I think when people ask about Mozilla controversies they're thinking about situations in which Mozilla has "broken character" by e.g. risking users' privacy, not activism that is absolutely in line with Mozilla's stated goals (whether you personally agree with them and their interpretation thereof or not).
Heck, even Netscape Navigator started out as shareware. It was "personal use only" but most commercial users never bought a license. It was eventually defeated by Microsoft Internet Explorer, which was free for commercial use even before it shipped with the OS.
If there is any chance someone will attempt a paid browser again, it will most definitely be based on Chromium (or maybe Firefox) rather than written from scratch and no website will make any effort to test on it (just like barely anyone ever tested on Opera).
Developer tools is already invaluable, but there’s no reason it cannot be better.