There seems to be no logical link between matter and determinism (or ideal and indeterminism for that matter). And libertarian free will was first articulated by a materialist, Epicurus, and is defended at length in Lucretius's famous poem. The reasoning was interesting, too. Man is free. Man is made of atoms. Therefore, atoms swerve. Not a bad prediction about physics.
But in modern times materialists, starting with Spinoza, tended to reverse the logic. Atoms do not swerve ("God doesn't play dice"). Man is made of atoms. Therefore, man is not free. In fact, man is not free even if atoms do swerve. This is Dennett's idea of "giving libertarians what they say they want". Most libertarians were and are idealists or dualists. Contemporary libertarian materialists are few, but notably Kane and Searle.
This is understandable to me for the times of classical physics, which strongly suggested determinism. But if classical physics was such a strong argument for determinism why not take modern physics at face value. Why try to explain it away? Rather than reinterpret physics to conform with apparent facts, like Epicurus, or reinterpret facts to conform with physics, like mechanical materialists, contemporary compatibilists choose to reinterpret both, physics and facts, to conform with determinism, perhaps diluted by "chance". This is a thin rope to walk. Kant once braved it to do the opposite, to make room for free will. The tables have turned.
This must mean that determinism in and of itself must hold a strong appeal for materialists (and perhaps others), perhaps an instinctive one, enough to overcome the apparent intuition to the contrary. Where does it come from? What are the arguments for it? Why is libertarian materialism so unpopular?