From what I gather from what virt has said on multiple occasion, specifically the VGMix 3 panel at MAGFest, Prot didn't KILL VGMix, but he definitely put the nail in the coffin.
VGMix2 wasn't particularly what anyone wanted, and needed a lot of work. They couldn't really fix the code because deim0s coded the whole thing himself, didn't really comment or organize, and then disapeared leaving everyone kind of SOL as far as the site went unless they wanted to try to dig through it and figure it out themselves (I'm pretty sure richter did/is doing a lot of that). Once Prot took the site down, rather than try to bring back a site that was pretty broken internal already, they decided it was a good time to just take it down all together and iron out all their problems.
Which, from what I've heard, and from what I understand, VGMix 3, from a developer/backend/coding stand-point, is THE h0tness.
richter is sexay beast.