The lack of IPOs is not due to the fee structure of VCs. The incentive model however, continues to compensate them extremely well even though the LP's profit model is broken by SoX. Which would seem to mean that the system as a whole is broken, and that the VCs incentives are now a problem. This would seem to suggest that these incentives need to be reformed to fix the system.
More likely though is that VC will simply crash like housing before any reform happens.
All the evidence I know of suggests otherwise. VCs had the same fee structure back when there were lots of IPOs.