Earlier quoted context omitted.
OP was clearly specific: EXEC salaries, not engineers and developers. And I'm not sure I would want their current execs there even if they indeed worked for free, not to mention at their absurdly high, grossly underserved salaries while they butcher the company all the way down. So yeah, find me a way to finance Firefox only, and not the funny projects, and to ensure that not a single cent goes to their execs (neithe…
The person you replied to was specific as well. Execs are paid well industry wide. If you aren't willing to pay market rates then you aren't going to get competent leadership to manage organizations at that scale.
The usual counter argument in this type of discussions is that it's Google's fault, because they changed their sponsorship, and there's nothing the execs could do. And then the counter to that is why pay big salaries if there's nothing they can do about revenues. Back to square 0.
I wish Mozilla setup funds for each project like it was done for Thunderbird. Then the execs can be paid from sponsorships etc.. but I personally have stopped to give to Mozilla any money since that change happened.