One of the bases is that the government's charter (founding documents) is full of lofty ideals. But when you look at modern society in practice, most of them have been effectively nullified. And following the contour of the law, you continually see the little hacks whereby the government routed around the spirit of the higher constitutional/common law by using a procedural exception of allowing people a narrow loophole.
If you start with an assertion that the founding laws must still be in full effect (the fundamentalist mindset, effectively), then it stands to reason that if you can just find the correct loopholes you can cut through all the totalitarian cruft that was plastered on top. There's a lot of runway before individuals actually run aground from these theories (and social pressure to not admit when they've failed in a minor way), so you end up with the sovereign citizen social club.
(AFAIK what actually happened is that those loopholes were de facto closed via societal consensus. And to the degree that some of them are still effective, you're fighting an uphill social/economic battle to choose them)