It's not a fascination, it's just easier and better to have good static analysis when programming. That doesn't have to be a type system, but I think there is a lot of reason to think that a type system is the lowest hanging fruit for useful static analyses.
I think this sums up the pragmatics well. Brian Cantrell discusses in one of his talks what they did at Sun to ensure they were writing safe C. This was a substantial amount of tooling they had to build up. Type systems bring you this tooling in a well founded, logical way. And as you say, it's a good place to start, even if it's just to know how the puzzle pieces of your code fit together.
Yes exactly. I'm kind of a broken record on this, but the key thing is static analysis. It's just that with statically typed languages, the type system specification and its implementation give you a giant head start on doing those analyses. You can build other kinds of static analyses for languages without static types, but it's just harder and you're way more on your own; you don't benefit from all the work put into the compiler for the language.
