Why is superdeterminism generally regarded as a joke?

My personal (somewhat facetious) answer to that would be because people lack imagination. I don't think of superdeterminism in terms of conspiracies, but rather retrocausality, and do not find it ridiculous if phrased this way.

Basically, I don't believe there's really something like a physically significant arrow of time - just an arrow of perception of time. Reality doesn't care how we subjectively experience time as somehow flowing from one moment to the next.

Some anecdotal evidence for this: First, relativistic theories are reparametrization-invariant - there isn't really a preferred notion of time. Then, there's the idea due to Stueckelberg and Feynman that anti-particles are basically just particles propagating backwards in time, or the time-symmectric reformulation of electrodynamics. Also, there's the fact that in general relativity, we need to solve for a consistent space-time (which takes future 'boundary conditions' into account), with the aggravation that space-time might possibly have a non-trivial topology at the quantum level.

This is also the basic idea behiind the (somewhat naive) transactional interpretation of quantum mechanics.

Why is superdeterminism generally regarded as a joke?

My personal (somewhat facetious) answer to that would be because people lack imagination. I don't think of superdeterminism in terms of conspiracies, but rather retrocausality, and do not find it ridiculous if phrased this way.

Basically, I don't believe there's really something like a physically significant arrow of time - just an arrow of perception of time. Reality doesn't care how we subjectively experience time as somehow flowing from one moment to the next.

Some anecdotal evidence for this: First, relativistic theories are reparametrization-invariant - there isn't really a preferred notion of time. Then, there's the idea due to Stueckelberg and Feynman that anti-particles are basically just particles propagating backwards in time, or the time-symmetric reformulation of electrodynamics. Also, there's the fact that in general relativity, we need to solve for a consistent space-time (which takes future 'boundary conditions' into account), with the aggravation that space-time might possibly have a non-trivial topology at the quantum level.

This is also the basic idea behind the (somewhat naive) transactional interpretation of quantum mechanics.