How rich is Steven hawking?

Answer 1

He makes the upper end of the salary available for a college professor, which isn't that much considering his medical needs.

He wrote a few books which were legitimately successful and so he makes royalties on that, as any author does. Is Stephen King(who's own contributions to society are entirely fictional) somehow less useful a human being because he's an author?

You iPod never would have been invented at all had theoretical physicists, much like Hawking, from the first half of the century not spent their lives theorizing "absurd" theories like quantum physics which nearly all of modern high tech is based on.