The DVD quality is low though. Unless they use Blu-ray it's pointless might as well use youtube.
You're right about music videos, but what about behind-the-scenes footage and album making-ofs? The only way we got those was through the bonus DVD, you rarely see labels uploading that sort of features on YouTube.
It depends on what's included. Mostly artists post interviews and stuff to YouTube about the album and such so there's really no need. I think if there was a Blu-ray included with 1080p music videos and HD content it would fair better.