If you're refering to Minecraft, one of the reasons why Minecraft blew up that much was that it was around at the exact right time in history: when online gaming had become viable and let's-plays were just becoming a thing. Minecraft, as originally intended, is a communal experience where you learn from the friends you're playing with and from sources on the internet. If I had to describe Minecraft in one sentence, it would be "let me show you that cool thing I saw Pewdiepie do last week". The idea has become commonplace in video gaming at this point, but back then it was fairly new.
(That said, opaque game experiences have been successful before, like the original Legend of Zelda. I guess the schoolyard served a similar purpose back then.)
