They adopted the crazy version scheme of Chrome, just to "keep up" (some people clearly have nothing useful to do in that organization). Then eventually they ditched its look to make it look like Chrome, which was heavily decried from the user base (apparently they have people to "think" about version scheme but none to think about users), enough to spur forks. Clearly, arrogant idiots have way too much power over there.
I still use it and have been over the last 15 years, but it's quite sad to see so many stupid decisions were taken by Mozilla. Just a few more I can think of:
* Get rid of their very qualified CEO Brendan Eich for something that had absolutely nothing to do with technology, only due to a totalitarian leftist/emotional/brainless subculture that plagues much of IT (cowards and low-life become brave when hidden behind a monitor).
* Kill development of Thunderbird (which is a thing, had and still has users), in favor of the ridiculous FirefoxOS, something that nobody asked for, never took off and is now dead and buried. One top reason why the Linux desktop is not taking off in enterprise setting is due to the lack of something impeccable to replace Outlook. We are still waiting.
* They had hundred of meeellions from Google in advertising in the past. That was so heavily squandered that it makes me unable to donate to Mozilla, even though I would very much like to support Firefox.