The bigger problem to me is that I have seen an untold number of open source developers that despise all manner of capitalism in the first place, so you can't even pay them to work on things. It's like they just want everyone to live under a rock in the woods and all be poor together or something. That's not going to progress society very much IMO.
I don't know the context of your interactions with them, but it is possible that they don't want to take on the burden and expectations that come with being paid, and so it just becomes a convenient excuse to not get tangled up in working on things in a compensated capacity.
To rephrase what I said, they explicitly tell you they are not interested in money as a concept at all. They prefer to have none... they basically want to have nothing and wish that the rest of the world believed the same thing.