A game that deserves these sales, regardless of everything that surrounds it. It's a game for a lot of people, but some will not understand why it has sold so many copies. And that's fine. I'm one of those that knows this game isn't for me, but I also know this game has struck a chord specially with children, and deservedly so.
I like to describe this game, for the children bracket age, as LEGO for them, only infinite times better than LEGO, apart from not being physical.
This game is wonderful for kids. Blocks are not only colored like in LEGO, but have real-world meanings like a block being made of grass, or wood, stone, and everything in between. This a great game to appeal to their creativity and a great fit for young people in many more ways than creativity.
As for parents, I'm sure they also like Minecraft. No LEGOs spread out all over the house and no need to clean the floor every time they play with them.
Win-win
But I'm sure someone already has said this all before.
Summing it up, I think there's a good reason it sells so much. Congratulations to the team.