A minor observation corroborating your hypothesis is looking at how many people Google's accumulated from the old Bell Labs (Rob Pike, Ken Thompson, etc.). In some ways the Bell Labs culture was the diametric opposite of startup culture, with a typical career path of "stay in this job for life", and little interest in business or striking out on your own. I believe a few have said as much, that they moved to Google because it was a place where they had the resources and freedom to just focus on technology.