It's certainly not dead; there's still an active community, even if it's not public. I know so many individuals who play the game on a regular basis. It's one of the greatest games of all time.
I'm amazed it's $20, bought it in beta for $5-$10, can't remember the price. I still enjoy it from time to time, allows decent creativity and the latest updates look ok. I'll pick up Minecraft: Dungeons when it comes out for sure.