No one has an issue with the notion of creating a technology that allows paralyzed people to control a computer with their mind.

Where people have an issue is that Musk was told multiple times by multiple people that an implant likely will never be 100% feasible because the brain moves around in the skull, making keeping a connection tricky at best and likely impossible. (hence why the threads have retracted)

He’s been told on multiple occasions that a non-invasive tech that is both more reliable and less risky is actually FAR more feasible. But his ego and his hard-on for being “edgy” basically makes him want to do things as “sci fi” as possible because a node that sticks to the side of your head isn’t as cool as an implant (to him).

Nolan would be just as happy. Just as capable. and just as helpful to the research with something less intrusive, but then Musk wouldn’t think of himself as cool.

tl;dr - No one has a problem with the concept. But the invasive way it’s being implemented is 100% because of Musk’s ego driven self-delusion of himself.