Twitter people can go lots of places, both competing social networks, and also various other internet-related or software places. Tesla people can go to lots of different competing automakers. But I don't see anyplace nice for SpaceX people to go.
The list is actually pretty long: https://en.wikipedia.org/wiki/List_of_private_spaceflight_co...
And that's not counting nation states.
Going to work for the Chinese or Russians? Well.. as long as you’re not planning to ever go back home.
There aren’t that many options for people who want to be a part of a team that actually accomplishes something significant.
Rocketlab and others even have products which standardize the bus part of the sattellite or probe, so you just attach your science experiment or sensor.
Shockley probably thought the same in early '57...