Ask HN: Exclusive Opt-In Search Engine?

What do you think of a search engine in which websites "register" to be listed on?

The exclusive element would come from restrictions as to who can apply. Off the top of my head, not websites with cross-site tracking, no websites of a commercial nature, of high quality, etc.

The idea sprung from wanting a search engine that only searches blogs of indie hackers/scientist. That's just my interests though, I was hoping to broaden that scope.

Basically a search engine that shows original, high quality content - with no financial incentives.