I remember this discussion when I was playing violin in high school and college (quite a while back), but it seemed like professors and violin teachers talked about surpassing Strads as a goal that might be reached someday, and that people were working toward. It never seemed to me like something the music community thought could never be achieved, like there was something mystical about it. So I'd chalk it up to time, not gullibility.
Since at least the 80s, modern instrument makers have been trying to duplicate and reverse engineer the Strads and try and make a modern instrument that's equally good. And there were tests like this, but when they were performed, the Strads would win out consistently. But now it looks like they finally succeeded. And we're entering the age where even outside blind tests, performers are starting to recognize this, like Yo Yo Ma and his professed affinity for carbon fiber cellos (I think he appeared on "How it's Made" a couple of years ago when they were demonstrating their construction).
I think you're right that it's not amazing that we'd get here eventually. In any theoretically achievable goal, where you're not trying to break fundamental physical laws, time, effort, and innovation win out. It's just like building better computers and programming them to beat chessmasters. At first, the technology and the programming just wasn't there, and computers lost. Now it is, and they win.
What this test doesn't say, however, is that the best of the modern violins are cheap. They aren't. They may not be the historical artifacts that Strads are, but they aren't something your average highly ranked college student performer could afford to perform on. I remember how prices ran, even for decently good modern instruments. This may bring the cost down from the tens of millions to the tens or hundreds of thousands, but the instruments they're comparing with are still astronomically priced, from most people's perspectives. They're the product of decades of research and mastery of the craft by modern luthiers, where the work is one part art and one part science. Good progress, and a big milestone, but they're still probably decades from making the same kind of qualities common and affordable.