Because that doesn't do what people want/expect, if you have a key with a value that's not frozen it will still be mutable, which indirectly mutates your objec

Because that doesn't do what people want/expect, if you have a key with a value that's not frozen it will still be mutable, which indirectly mutates your object. See the example at https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Object/freeze https://developer.mozilla.org/en/docs/Web/JavaScript/Referen... about modifying internal.a