Minecraft is not an online game, it has a multi-player option sure.. but it doesn't strictly need to be online. There is a single-player mode since basically forever..
I'm not arguing your point, but this is the general state of gaming today. A significant portion of "single player only" games require you to be online, contain "online" content, and access to the game can/will be effectively removed when servers/services go offline.
It's a sad state of affairs that you can buy an offline game, and then the developer/publisher can push out an update that turns it into an online game and then disables your access to it
