The reason is simple: I got a Blu-Ray and not an HD-DVD player, and I always have the impression that the technology I go for will be the one that won’t be the standard a few years later… but right now, all indications are going into the other way. While HD-DVD had an initial “first-to-market” advantage, Sony’s decision to include a Blu-Ray player in the Playstation 3 has dramatically shifted the game and enabled this format to overtake the former within a few weeks.
As for any new technology introduced, being the choice of the early adopters and the market leader while adoption hasn’t reached the mainstream users is in no way a guarantee for success. Offering the best or most advanced feature set is also a no indication of becoming the long term leader. We’ve seen this over and over again, from Apple Macintosh to the Palm. Being backed by Microsoft can help in the long term, but the iPod / iTunes offering is (so far) a proof of the opposite.