Looking at https://www.mozilla.org/en-US/foundation/annualreport/2018/ https://www.mozilla.org/en-US/foundation/annualreport/2018/, e.g. the "Combating Misinfor

Looking at https://www.mozilla.org/en-US/foundation/annualreport/2018/ https://www.mozilla.org/en-US/foundation/annualreport/2018/, e.g. the "Combating Misinformation" is not something that I'd consider one of the core tasks of Mozilla. I would also assume that there are conferences, grants/sponsorship/stipends, CEO pay, etc. The audited report lists conferences/conventions meetings and advertising/promotion, two items that some may not want to contribute to. I'm making no judgement regarding whether these expenses make sense or not, just pointing out something that someone who wants to finance Firefox and MDN may not want to contribute to. Of course, unless you trust the organization to actually honor the intent behind a donation for a specific purpose, such donations are moot as long as the organization receives enough general-purpose donations: They can just put 100% of the money tied to a specific purpose behind that purpose, but reduce the amount of "general-purpose" money that would otherwise have gone to that purpose by the same amount.