I don't think you understand. If you don't allow null by default in your type system then you don't have to check for it when you don't need it. Dealing with u

I don't think you understand. If you don't allow null by default in your type system then you don't have to check for it when you don't need it. Dealing with user input is a separate issue, yes you need to validate it. The problem with every type allowing null is that it infects EVERY object for a situation that isn't always needed or wanted.