Doesn’t this also apply to closed source software, but with the extra downsides that you can’t fork it etc.?
I contribute to open source software because it improves stuff I use and/or care about.
It seems too pessimistic, IMO, to abstain because things could potentially change to the worse, sometime in the future.
Contributing to closed source usually involves getting paid for your work.
Yes, I think they're pretty much saying they don't want to contribute to projects they don't own.