Just imagine not being from the US, donating to Mozilla so they improve Firefox, and they instead spend the money on translating the USA presidential election.
Right now my parent is getting downvoted but I think that there's a great truth in this comment:
A lack of focus generally hurts an organizations legitimacy in the eyes of it's donors.
Increasing the quality of a countries national elections isn't a goal I'd immediately assume to be part of Mozillas mission, so I'd be disappointed about such a project.
They could go the more transparent route and create a second organization for funding things their management likes.
... but I assume that such an organization would probably have some funding problems.
Sort of similar reasons; while this is true, it’s also that we aren’t sure how we’d allocate that money if we got it. Discussions about a possible foundation for Rust are ongoing, and these kinds of questions are a big part of why that hasn’t happened yet.
Part of the reason for that, I think, is that Firefox development is done by the Corporation, rather than the Foundation. The Corporation's can have far bigger income streams (i.e. the search engine deal), so it makes sense to make that responsible for the development of Firefox - even though that means you cannot donate to it.