I've head that there are tax problems with that. So maybe there needs to be a paid "Firefox Pro" or whatever?

I mean, isn't that the problem? They made 500m this quarter so a <1m donation box won't shift things. Hell, it may not even pay for more than a few devs given the compensation I've seen.

There simply isn't enough goodwill to maintain the living of even a single person operation without some sort of incentive (which ceases to be a "donation", but a subscription with a fancy coat).