Conventional wisdom in classical guitars ALSO says the guitars have a lifetime. The wood is tight, then it opens up, and then it breaks down gradually over time--roughly 15-20 years for cedar tops and 40 years for spruce tops.
If that is actually true, I suspect that feeds into this study. The Stradivaris, while phenomenal, are long past their peak and are now at the point where they are breaking down from playing and are likely only being preserved by the rarity with which they are being played.
I wonder if the "moderns" used in the study actually had some mileage on them. It would be interesting to see if a 20 years old "modern" with heavy use actually scores better than a 5 year old "modern".
Overall, it's actually good news. I suspect that this is like modern classical musicians, the geniuses are as rare as ever, but the average level of achievement across all classical musicians is WAY higher now than it was even 100 years ago, and certainly moreso than 200-300 years ago.
It means that those of us who can't afford Stradvaris can still get excellent instruments.
No, it's not, because the same long-term relationship can happen between a player and a modern violin as well.