Based solely on a Libertarian Linux group's poster I saw one time, I suspect the unregulated nature of things: people provide and build their own software, no one telling you what you can and can't build. I don't quite know how to summarize it succinctly but do you kind of see what I'm getting at? Since a lot of FOSS is communities self-organizing and decentralized (by choice, not by edict, since right wing Libertarians clearly have no issues with heirarchies so long as it isn't a gov. mandating them), I can see it being very appealing.

I suspect they absolutely insist on permissive copyright, though, so all the communal work can be easily exploited and stolen for the financial benefit of a few companies because something about the NAP and not restricting freedom including the freedom to be exploited.

Have you heard of lunduke?