More charitably, it's driven by frustration more than speculation. Browsers are old technology, and some people think that maybe hurling huge amounts of money at stuff like this is unreasonable because projects can/should be "finished" at some point. Forever-development is very often actively harmful, and if it's actually
necessary then it might be hiding problems in the wider ecosystem.
It's good that we have alternatives to chrome, but on the other hand the alternatives are not winning, and they prevent any chance of regulation (or having a reasonable discussion about whether chrome sucks, as we see here). There's a strong argument that mozilla IS google's antitrust shield.
Also can we just take a minute to seriously try to imagine the leader of the "Makefile foundation" receiving $2.4M in compensation, and generally burning a lot more money on dead-end "innovations" and then rebranding as "OpenSource.. And Advertising". Make is 20 years older than Mozilla, but does it look like the browser project will be finished or moving in a great direction any time soon while there's big opportunities for grift and graft?
Signed, a grateful but nevertheless annoyed and skeptical firefox user