I was skeptical too. But after reading the JEP i think i am convinced.

It makes an analogy to packages. We allow classes to exist in the default package. Therefore, I think it's reasonable to allow methods to exist in a default class.

Of course you shouldn't so this in real work, but that's also true of the default package.

I also like that main doesn't need an argument. Many noob programs don't even use the String[] args parameter anyway, so let's not require it.