I'm surprised myself that someone on HN is really claiming that Google doesn't edit search results for all sorts of reasons, including for purposes of social norms, of any sort, and social responsibility. In fact, every person and organization does that. I doubt there are any social interactions where people don't behave according to a set of rules.

> why are they surprised

Nobody said they are surprised; that's not relevant. They are trying to solve a problem, just like people who are working to resolve the problems of cancer, gun violence, and bugs in Firefox.