That is very much not true and even less true when the blu-ray release comes from a new master that isn't limited by older technology.

If you are right and I am wrong, then that very much goes against the public perception. The switch to DVD was pretty quick and universally pretty well received. So the public was very much willing to spend their money and time to make the switch for the extra quality (or maybe the convenience) of DVD. The switch to Blu-Ray is still ongoing now what 20 years later, and it looks like it will never be complete.

In the eye of the public the quality of DVDs are obviously good enough, and the jump to Blu-Ray is simply not worth the time and effort to make the switch.