Too many people are saying this.
Progress halts when you say something is "good enough". For years people said VHS was "good enough". LaserDisc, SVHS, ED-Beta all failed because VHS was "good enough".
I have HiDef. I love it. Standard DVD is NOT good enough! The difference starts to get really noticable on larger sets. Added color definition and dimensionality are apparent on even the smallest of monitors, though.
With the "good enough" attitude, we would never have OAR, Dolby Digital & DTS, etc. Blu-ray offers lossless sound, 3x resolution, true color space, and more. DVD technology is a decade old, folks.