And I disagreed with that. Some games calling themselves "early access" are essentially (or literally) finished and largely bug-free. Some games described as released are a mess. Who stops them? No one. Am I saying that is good? No, it just serves to confuse buyers about what to expect from their purchase in many cases. But much of the time that confusion is the entire point of the exercise.
That's a pretty normal player activity trend for SP games. Huge release numbers that taper off after three or four months. Nothing short of DLC gets people to stampede back into activity, something I had to actually go out and graph like a year ago:
That's also why I'm doubtful mods are going to bring back players in numbers enough to matter.
Of course, what benefit high playercount actually brings to a mostly SP game with zero in-game monetization is itself a question worth asking.