He's been the sole maintainer on the project since 2012 [1] and has never been compensated for it, he says it will always be free to end users but wants companies that are financially benefiting from it to help sponsor continued development [2]:
> I will never ask end users for financial support. FUSE will always be free. However, what I'm asking for is for companies, that are selling FUSE-based products or rebrand FUSE and bundle it with their apps, to re-invest some of the profits in the continued development of FUSE on macOS, if they can afford it. I don't think that is unreasonable.
So he's just exercising the same BSD rights that all the other companies who have been taking and commercializing his work and not contributing back any fixes or funding for continued development.
Given that the alternative was to abandon the project [3], the only way it was going to see continued development as an OSS project was is if others took over maintenance/development of it, which anyone is free to do by creating and maintaining a fork.
[1] https://github.com/osxfuse/osxfuse/graphs/contributors
[2] https://github.com/osxfuse/osxfuse/issues/590#issuecomment-5...
[3] https://github.com/osxfuse/osxfuse/issues/590#issuecomment-5...