Choosing how to respond to a query string is the very nature of what a search engine does. It's utterly impossible to have one without the other. The more charitable interpretation of your argument is that there should be more "neutrality" in the algorithm, but that's also difficult... Should they be neutral to whether or not people are trying to manipulate algorithms with dishonest SEO? Should they be neutral to what other users like? Neutral to who else links to the page? Who decides which neutrality prevails where they conflict? Who decides if a certain kind of neutrality is more important than user preferences or market demands?
This is a rabbit hole of mutually exclusive goals and inevitable trade-offs that requires complex judgment. Government regulation in this area would be extremely difficult and troublesome, not just for economic reasons but also for first amendment ones. Free market competition in this area is going to be limited due to economies of scale, so that isn't perfect either.
And if you think that imposing traditional publisher liability for search engines is likely to make search engines censor _less_, you might want to think a few steps further down the strategic consequences.