not sure how old you are… but there was a time when everyone used VHS tapes, not DVD’s. And there were some people that asked the same question you did… and DVD’s are here, go figure.
I think Blu Ray is a great idea, I do on the other hand accept technology easier then most. However, sony does not push new technology very well. They have failed at pushing technology such as beta max and Mini Disc. This scares me that they want to push a game console with so much technology.