Fwiw - my general premise isn't that the "majority of VCs are not good investors." My point is that there's a serious disconnect in the markets right now, and that it is rooted more in fear than a lack of opportunity.

On the second point - you're right that the cash isn't literally sitting around, but VCs (generally) do not have to ask LPs for approval on a deal by deal basis. Capital calls can happen either as tranches or in response to a deal, and it is unusual for an LP to successfully refuse a capital call because of a specific deal.