Wealth is created when people take existing resources and transform them into something of higher value. Money is simply one very liquid type of input that a creative entrepreneur can use to create wealth.

If the marginal value of more investor capital to web entrepreneurs falls below the cost of acquiring and managing investors, then predictably web entrepreneurs will stop seeking capital. A more interesting insight, though, is that long before things get to that point, smart investors should be seeking to deploy their capital to ventures that can actually use the money to produce a better return. If capital is no longer the limiting reagent in web startups, then the money should go to places where money is the limiting reagent, and consequently has a higher value.

It's worth noting that Kleiner Perkins, as one data point, got out of the web startup business some time ago and has been investing in energy and biotech.