I can certainly see the entrepreneurial aspect of being a professor -- managing a lab, hiring and firing people, and sourcing funding, and I don't disagree that professors are there to inspire the next generation. However, there is still a part of me that feels professors have that "safety net". Tenured professors are paid a monthly salary by the university, and often times at / above industry (that's true at least in Canada anyways). With a steady income, they have no risk, and the risk factor is a big part of being an entrepreneur.