Yes, there is a huge difference between type checking a minimally type-annotated program, and dreaming up a rich type system just because you could (I should know, I used to be a Java dev).
You're giving yourself away by making that comparison - your experience as a Java dev gives you minimal insight into the expressiveness or utility of TypeScript's very different, much more powerful type system.
It's not about the expressiveness or utility - it is about types you write (bad) vs types the type checker generates and maybe shows you in an IDE (good).
The point being that people should write actual code, and should not write type code, simply because given an opportunity to write things, people will indeed write things, whether actually helpful or (more likely) not.
