I'm not them, but there are few things better for operational insight than the JVM. It has a boatload of tuneables, it has a very rich dynamic code load mechanism (Reflection, ClassLoaders, the new Modules system, and it used to have a strong sandboxing system but they killed that), and at the intersection of those two things is JMX, which is dynamically tuneable deployments via API. It's like having JVM-local feature-flags that one can twiddle without needing to bring down the JVM

And sure, it's not everyone's cup of tea, and/or plenty of people will chime in with "yes, but"s to defend golang or every other platform that isn't the JVM. I'm not yucking your yum! I'm just saying for me, the JVM is the bees knees