This is seriously entitled. Mozilla gave us an amazing resource, entirely for free. This attitude isn't right, it's toxic and harmful.
Mozilla is in a spot of difficulty, and instead of taking a resource that is operating entirely at a loss down, they're taking the engineering steps to ensure thez resource can outlive them.
That their mismanagement caused them the difficulty is entirely irrelevant here. It could have happened in a myriad of other ways. We should be praising Mozilla and the MDN tech team for the steps they're taking in making sure the MDN can live on.
Hint: it's less than $200.
Donations don't really work.
Just to be sure, are you referring to the "BuyMeCoffee" button on the GitHub page for the extension (https://github.com/VSCodeVim/Vim)?
That's what I expect of a non-profit organization dedicated to maintaining one of the last two remaining major browser engines, yes.