@Gargron A US based 501(c)3 lets you accept US donations that are tax deductible. It doesn't grant any magic powers to Americans, or tech companies, or even Silicon Valley.
Being able to accept donations from US citizens in a tax deductible way, gives Mastodon more chance of surviving without needing to resort to VC driven commercialization, or block chain schemes. This is a good thing.
I get that people are (rightfully!) suspicious of any change, especially those that involve boards.
