But I'd look at people a bit oddly if they said: 'We didn't want to set up CI caching and compiled languages took 30 minutes per run so we changed our entire codebase to python'.
Maybe it makes sense for them, and caching across dynamically spawned VM's is admittedly a harder problem which most build systems aren't great at, but still. I can easily believe that getting build caching to be reliable would be a lot of work, but is it more work than a full rewrite of a significant codebase?
Or if staying on Linux, JVM snapshots.
Secondly, there are several ways how Java source code becomes machine code, depending on which JVM and JDK is being used, not taking into account the ART cousin.
When the potential set of behaviors you could write a program to have is infinite, but the actual behavior you want is singular, a programming language is more importantly defined by which ones it eliminates up front than which ones it lets you write (assuming it lets you write the one you want at all, but that's almost always going to be the case for most general purpose languages). Bugs are just false positives in this framing, where the program you wrote seems like the one you wanted, but there's some divergence between what you thought you were getting and what you actually got, and catching some of those up front is a huge part of why type systems are so useful.