The issue isn't so much whether it is null, but whether it can be null. Because if it can be null, you have to check whether it is null before you can actually

The issue isn't so much whether it is null, but whether it can be null. Because if it can be null, you have to check whether it is null before you can actually do anything with it. That adds a lot of null-checking boilerplate to your code. If instead the compiler can guarantee that a value will never be null, then you don't have to check, leading to cleaner code. Scala does this with the Option type, Typescript by forcing you to declare a type as `string|null` if it can be null. These sort of things make your code safer and cleaner.