> I remember a few decades ago somebody saying the JVM was incredible technology, and as a user and programmer I still have zero clue what the hell they could have been thinking was good about the JVM.

I see what you mean. In that case we can add Scala backed systems as well to the JVM balance sheet. If we simply look at the JVM and the systems it backs, there's very little evidence that it isnt a marvel of technology. It powers more impactful systems than few other technologies.