There's no one simple reason, but a big contributor is compensation. Government pay for high skill professions like computer programmer, mechanical, electrical,

There's no one simple reason, but a big contributor is compensation. Government pay for high skill professions like computer programmer, mechanical, electrical, and aerospace engineers, etc is far below what good people in those fields can make working in private industry. Often people in those fields work on government contracts, where the US Govt will pay 3x or more than their already high total compensation for the privilege of their time. I should know, I'm one of those professionals. I started out working for the government, then eventually became a contractor (doing the exact same job in the exact same building that I had done for the government! for 30% more money!) It was hard to not take that offer of the additional money, especially when the government would go out of its way to infantilize its employees.