It's not clear because any act of curation then becomes censorship, which is a uselessly broad definition.
It's basically the same thing when the store you have has the kind of market share that Steam has. Just like Microsoft had certain obligations regarding what kind of software they bundled Windows with and allowed / disallowed certain apps, etc. because they had a monopoly over a market, Steam has certain perceived obligations, albeit not legal ones, when it comes to curation.
Everyone is entitled to their own curation. For instance, Apple Store censors porn apps. That's the correct word: censor. It's also pretty much an uncontroversial censoring, but it's still censorship. They will call it "curation", which is the neat word of today, but censorship is what it is.
Why are people denying the proper semantical usage of this word is something that baffles and concerns me. NGTM's argument is that the game was "bad" therefore it was merely curated out of Steam just like every other "bad" games. But there's little indication that this was the case, that the problem was "quality". It was most assuredly the game's "problematic content" that got them squirming. IOW, it was the social, political
content of the game that caused it being out in the first place. I also have little evidence for it, because there was no official statement by Valve by then, just this little snippet:
"Based on what we've see on Greenlight we would not publish Hatred on Steam. As such we'll be taking it down," Valve's Doug Lombardi offered to Eurogamer.
The fact that Gabe reinstated the game himself is proof enough for me that the problem was never one of quality, but rather of content. And if the problem is content, then yes, it's censorship. The other argument where it cannot be censorship because the criteria (ultraviolence) failed to censor other games like GTA, etc., is just nonsense, flat out silly at its face, since no one has ever argued that it was a consistent, coherent decision. It was obviously an emotional decision from someone in Valve that was disgusted by that game and drew the line "No this **** won't do"
. Which seems like a human, pretty okay decision to be made, except Hitchens was glorious in his defense of free speech when he stated that it's precisely the most ghastly speech that needs the most
protection, not the least. See my last youtube link for details on why this is the case.