I personally don't believe results should be removed or altered based on human judgement. What if I decide to start a competing service that Gabriel takes a dislike to? Or decide to start a hate site for DDG[1]? Do they not deserve a place on the internet? Is it up to one person to decide this? For neutrality to work it needs to be neutral for absolutely everyone, or atleast that's how I see it.
[1] These are purely hypothetical. I'm a big fan of both Gabriel and DDG, and I'm not suggesting he would ever do these.
Of course all search engines are "based on human judgement". Is it different if you write a fancy algorithm that detects these and removes them vs. just deleting the site from the index? I don't think there's a difference.
[1] These are purely hypothetical. I'm a big fan of both Gabriel and DDG, and I'm not suggesting he would ever do these.