Funding is a necessary but not sufficient condition. They were the right people, in the right place, at the right time. Off all of those, the time period, i.e, the beginning of the computer revolution, is the most important factor in my view.

There are certain moments in time where such innovation is possible and this was one of them. In this respect they are like The Beatles--the right talent just at the right time.

There isn't anything like Xerox PARC at the moment and won't be until the conditions are once again ripe for another Cambrian Explosion (as another commentor aptly described it) of innovation.