> My suspicion is: someone in dire need of intellectual engagement might want to work at Tesla simply because of the opportunity to exercise one's mental capacity in a challenge of equivalent magnitude. (Not Tesla specifically: I suspect any company with similarly-driven heavily-pushed technical production would suffice, for a person with the knowledge of that sphere.)

I feel like you're over selling this by a lot, especially the Hawkings and paper comparison. Someone moving from Google to Tesla because of "boredom" is likely due to the industry more than the intellectual challenge. People go to work at Tesla because they believe in Musk's "vision" of a better world.