Bang on. New instruments of finance/investment (public companies, bonds and shares) and the legal institutions that arose at that time to protect investors were one of the most important catalysts of the industrial revolution, possibly the most important driver of productivity growth in the history of mankind.

You could argue that eventually the finance industry becomes so large that it reaches equilibrium within the markets it operates (Mervyn king has suggested the same about the City of London), thus becoming zero-sum, but this nuance is completely absent.