Minecraft isn't dying it's just not growing as quickly.
Ok here's the deal. Minecraft got really really popular a couple years ago. Now, some people aren't doing it any more, but a lot of people are still. Most people in most countries who would play it have heard of it. Most of the newcomers will be trickling in in the form of five year olds who just got pocket edition on the ipad. When they get older, they might get it for the pc. At this point, Mojang just needs to grow generations up with the game.