Shame they didn't link to their annual reports or something../s.
Turns out aggressively developing one of the world's most popular browsers, a mobile browser and a mobile OS costs a lot of money. $100m for software development, $20m for admin and $17m for branding/marketing.
They are non profit so there is no point in keeping money in a box. You might perhaps hope they got a little more done for that kind of money (conservatively 800 full time devs.. main gripe would be a faster JS engine), but i guess large organisations aren't too efficient.
800 full time devs? No, maybe 800 full time employees (I would say less when you account for much higher salaries at the top as well as costs like benefits, pension contributions, etc.). In a software development organization of that size how many do you think are actually writing code? Maybe half?
Engineering management, sysadmins, quality assurance, release management, support staff at each location, etc. all go into that $100m figure.
I couldn't find global stats, but at 2.72 billion[1] and 3 billion[2] USD respectively, the apple and orange industries have revenues far in excess of Mozilla's.