Why does a thread outlive the main method in Java?

Question

I was teaching myself Java threading and I noticed something that confuses me a little. I made a class called engine implementing Runnable. The r

Answer 1

Because that's how it works. The program exits when System.exit() is called, or when the last non-daemon thread stops running.

And it makes sense. Without this rule, every Java program consisting in just spawning a GUI, for example, would have to wait() infinitely to avoid the program from exiting immediately.