there's an ending to minecraft? i'd probably play it if it had a quest system like starbound.
I think it's an issue with Minecraft. They expect you to go and talk to people like with the original Zelda, or do some online research to find out about:
A) All the craftable items
B) The existence of the Nether
C) How to get to the Nether
D) The existence of the ending
E) How to get to the ending
But I don't think that works as well as it should. That said, I don't know if a quest system would match the style of Minecraft. It's very focused on the player story, and they have in-game tools that allow you to express your in-game story (such as the journals/books). I think that any kind of designer-imposed story (aside from the end) would have a large impact on the game.
Minecraft didn't have 3 sequels in a year and the developers actually cared for their game
Here here.
I find it amazing how long they've been able to keep pushing it, and how its popularity continues to burn bright. Maybe one day they'll finally get a real engine and stop using the awful and unoptimised Java, though.