And then people simultaneously complain that Mozilla is reliant on Google for funding. There are not many good revenue options available for a browser other than selling search defaults - and AI may start choking off that revenue as well - but Mozilla also can't touch AI without being screamed at.
I mean, even literally this one sentence is self-contradictory. Thunderbird is not their browser. You complain that they "invest more effort into everything other than their browser" and then complain that they don't invest enough in Thunderbird.
No win situation for them in terms of public opinion.
* They can't get diversify their revenue to be less dependent on Google without doing things that people view as "distractions"
* They don't get credit when the "distractions" are for the public good, like LetsEncrypt, Rust, Opus / AV1, etc.
* They get punished for de-prioritizing "distractions" like Thunderbird and Servo and Rust because those distractions are popular.
* For years they were simultaneously being dragged for dropping the XUL extension ecosystem, and also dragged for low performance and lack of multiprocessing and a bunch of other things which were being kneecapped hard by the XUL extension ecosystem.
It's not like I love their management or anything, certainly they've made mistakes, but the narcissism of small differences hits them with full force relative to every other competitor in the space.