I'm surprised that more Microsoft and Amazon money hasn't worked it's way back into the Seattle tech echo-system. Is it a lack of VCs, rather than a lack of seed money and engineers?
Many qualified investors around Seattle are nervous to enter the Angel/VC game. Seattle Angel Conference is working to fix that issue. Introducing both investors and companies to the process. Investing about $200k every 6mo in Angel rounds
I can't answer that with definitive nature; my impression is that the virtuous cycle of senior folks with great exits becoming VCs doesn't occur as much.
Could the issue be that Seattle Microsoft millionaires are more risk averse than Silicon Valley millionaires? Recirculation of capital (with advice that follows) is a big part of silicon valley.