Mark Christiansen expounds on the why in QuickTime is the US Dollar of Digital Video.
You really do have to wonder if Apple fired all the QA employees or what. And things may evolve but with the transition to Snow Leopard and the iPhoney-QuickTime X, it seems like the bumpy ride won't end too soon. It's an opening that Microsoft is unlikely to fill and Adobe is just getting going with Flash MPEG-4 and CinemaDNG.
By the way, the Windows stripper utility for the QT gamma tag is around.