I'm guessing this means arguments about how "The Hobbit" has actually changed the life of a lot of people (people who made money from it, people who spent time reading it, people who spent time making a movie, people who spent money on that movie, people who made money from the movie, etc. etc. etc.) or even improved it in some less-measurable way (used in a literature course, philosophical discussion based on the book, inspiration from the story of the book for doing something else in real life or to spark a real life discussion, etc.) will have no meaning for you, since all of this is obsession with Imagination and it's not the Real World.

I mean, my day job consists 100% of putting the right numbers in the right places in a completely virtual system that is entirely meaningless in the real world, that I cannot interact with and cannot use. These numbers don't do anything, they don't change anything, and they certainly won't build a treehouse I can go hide in when my parents get overbearing and obsessively controlling.

However... my day job consists of managing an entire Enterprise Resource Planning system, and the numbers I put in the right place are the resources of this company. The right numbers mean that people looking at them later on will get the right parts at the right time, and build things faster, and eventually clients will have their product on time and at best quality. The wrong numbers... well, 2+ year late deliveries and 2-million-dollar penalties are called "getting off easy" here.

So you see, your idea of what is imagination and useless, and what is "real world" and practical, definitely isn't relevant to the problem. The real question here is: Comparing between a childhood with minecraft, and a childhood without minecraft, which childhood will produce the more happy and productive and overall enriched humans later? And that's not a question about what you, as a parent, consider to be Real World™ or Imagination™. It's a question about what skills and what abilities and what methods of thinking the children will grow up with, and how they will apply and be able to use those abilities later in life.