Earlier quoted context omitted.
As a developer, I want npm package information and docs to show up in search. What case is there when you want to find a package in NPM, and information about that package, using Google? If you want information about the package then it's find if the NPM package page is missing from the results - so long as you're getting the package's homepage or git repo then that's plenty. From there you can get to it's NPM page.…
What? Nearly every time I search a package name in Google, I'm trying to get to the npm page. And I want to find the matching npm page so I can click from there to the associated GitHub, since it's the most trustworthy way to know I'm browsing the source of that specific package.
This is exactly the point I'm making. It's very rare that you want both NPM package pages and internet results. If NPM wasn't indexed it'd solve the spam problem, and the only cost would be people would need to think about what they're looking for and use NPM's search instead when they want the package page.