Yes, it is well and truly a broken and highly deceptive tool, widely referenced for all the wrong reasons.
Possible reasons.
Another broken tool for this purpose is the whole-song waveform plot. You know, the one that looks like a “crew cut” or brick wall. Highly misleading as a guide to dynamic range. See video
here.
The worst thing, is that it has gotten to the epidemic stage of confirmation bias and positive feedback. People are routinely imagining confirmation of the DR scores when listening to the music, even when there is no difference in the dynamics of the music itself, and this firms their mistaken belief that the DR scores are reliable. The above video link is an example of this. So is the Random Access Memories (RAM) album: the vinyl measures a DR score five points higher than the high resolution download, but it has been confirmed that the vinyl was mastered from the high resolution download. Despite this, people are routinely reporting that they hear the dynamic range of the vinyl as substantively higher than the high resolution download of RAM. It has gotten to the stage where, purely by the reputation of this database, people are confirmation-biasing that CDs and digital downloads sound compressed compared to vinyl, in general. The poor sound engineer who made the above – linked video found himself inundated by people claiming that they could clearly hear the higher dynamics on the vinyl sections that he was playing on the video. He had to issue a follow-up statement that people who were clearly hearing extra dynamics on the vinyl, trusting their ears, simply had to “let it go” — because it’s impossible. That’s how bad this issue has gotten.
Bottom line: if you are seeing DR scores in the range of six points higher for vinyl than for digital conditions of the same music, and when you listen you confirm that the vinyl sounds substantially more dynamic, you really need to put aside this finding and stop over-trusting your ears, because you might as well be confirming by ear that cables sound very different. The same mechanisms of deception are at work.
Cheers