What incentive would hardware venders have to provide open source drivers for a tiny enthusiast operating system? No other OSs have had that requirement. It's hard enough to get working binary drivers.

I don't think that all the Linux driver issues would be solved with the release of source code. Driver code already makes up a large majority of the kernel. The sheer amount of code contained in binary drivers would dilute the already relatively small number of volunteers available. The best way to increase the quality of Linux drivers is to get venders to invest more in Linux driver development. The only way to do that is to vote with your wallets by supporting Linux friendly hardware, and increasing the size of the Linux market.