I use Java today daily, and came from Node. It is slower to have the compile step, even on very powerful machines, dynamic types are faster to change, and there are many caveats to hot reload. The repl comment was about is about speed, not sophistication. When something happens instantly versus a tiny pause, you don't think about seeing your change immediately on save, versus batching many changes together and then testing them. This turns out to be faster for me for explorative work. Many people agree. Just trying to explain. /shrug