This doesn't sound like the problems are hiring ex-Microsoft and ex-Google people per se. It sounds more like a typical problem with managing a remote office, where the remote office isn't operating the way the home office wants. The telling part to me is:

Musk quickly brought in new managers from SpaceX headquarters in California to replace a number of the managers he fired.

This seems like a good sign to me. It's hard to convince people with experience at your company to move cities to start up a new remote office, but it's an important part of getting the culture right.