Neurolink is easy to understand. Elon Musk's values lie in the fact that he wants the legacy of being the one to establish permanent human presence on Mars. it really is that simple. Humans are adapted to living on earth. Living on Mars, in low gravity and low atmospheric pressure, will require fine motor skills operating machinery that are not natural to people. People will over correct. Neurolink solves that. It really doesn't go any deeper than that.

He is not concerned about how the technology might be used or misused. He needs it for a Mars colony. Every decision Elon Makes (except for Twitter, as far as I can tell) is for Mars. Boring tunnels? Mars. Neurolink? Mars. Space-X? Mars. Solar energy? Mars. Electric vehicles? Mars.

It is pure ego. There is a good interview with someone who works for him on Youtube. The employee compared him to Howard Hughes on camera, and later became worried that might be interpreted as meaning he was implying EM was eccentric. So he went to explain to Elon what he meant by that. Elon Musk apparently thought the comparison was incorrect, not for any sensible reason, but because HH never developed any technology that fundamentally left an impression on humanity.

Elon Musk is an extreme narcissist. He has a vision, and he wants that to be his legacy. There really is no reason to read more into it than that. And I am convinced he switched allegiances from the left to the white hats simply because he realized if he wants to see his Mars vision come to fruition, this is where he needs to be in order to make it happen.

Right with you.