If by null pointers you mean that some data is nil where it should not be, then certainly — they are a problem. In fact this is probably the biggest class of problems I encounter on a daily basis.

I still think you don't need a type system to address this. You could even argue that "nullness" is not a type, it's a data value (an out-of-band data value, shall we say). The way I deal with it is tests for corner cases (I always try to have tests that demonstrate what a piece of code does with null parameters), preconditions and assertions.

I agree that good static type systems can be of help, that is what I meant when I wrote that they seem to help some programmers. I don't dispute that. I dispute the other claim that I understood from the article: that languages that enforce a rigid structure are strictly necessary for "production software".