A thing that might be worth mentioning here is that Image & Form has a pretty good history with putting their games on Nintendo devices. The first Steamworld Dig, which was a 3DS Download title way before it came to PC did so well, that it saved the company, if I recall correctly. So it’s not all that surprising that the sequel did also quite well.
I’m always a bit wary with stories like this, because even though this one was quite careful to jump to any conclusions, it still kind creates the impression that there’s ONE reason why games do well on platform X, and not so well on platform Y. There are certainly common trends, but there are still a bunch of factors to consider that are sort of unique to each title.
One thing I can sort of agree with coming from my own experiences with Steam is that, if a game doesn’t do really well right from the start, it’s will get buried so deep that it’s almost impossible to recover from.
Better (human-led) curation could help, but also more ways to draw attention to already released titles. Videogame reporting moves so quickly that once a game is out for longer than a week, it feels like it’s completely irrelevant in terms of News/review coverage. This again makes it harder for devs to recover, should their launch go not as well as planned.