It has no benefits. They claim no one is complaining about the quality of regular DVDs and state many people are happy with the quality of the current DVDs. I don't fully agree with their opinion, IMO the higher video quality of the high-def DVD standards does offer benefits for consumers.
It has no customers. Well that might be somewhat true. Many people only bought a DVD player a few years ago and aren't interested in replacing it with a new model that costs x times as much.