It's quite simple: null is not a valid value for any type. It completely breaks the entire point of a type system. Null isn't an Integer, nor a String. Simple

It's quite simple: null is not a valid value for any type. It completely breaks the entire point of a type system. Null isn't an Integer, nor a String. Simple example that proves my point: You can't call .length on null, but you can for every string. Therefore null isn't a string. So why in hell should you be able to write code that states (falsely) that null is a string? You can't say an int is a string. Removing null from a language adds a tremendous amount of safety.