The incentive was US Navy feeling embarassed at how "country that invented the airplane" had shitty showing in aviation in 1914, and ultimately deciding to invest heavily in area now called Silicon Valley.

This provided demand for products and services that simply was not there in private form, allowing way riskier investments - all the way to 1980s Silicon Valley was mostly riding downstream of military procurement (Can't source the quote right now, but Sun microsystems be-or-not-be was landing a contract for NSA for Unix workstations - because NSA could frontload an order for few hundred if not thousands workstations)

I could have created a social network in my college dorm and had become a multi-billionaire mogul. What "could have been" is practically limitless.