I love world building. Ever since I was a child, I loved building things. I would create toys for myself out of construction paper. I would build structures (with secret passageways) with LEGO blocks. I would draw elaborate maps on grid paper for my own imaginary video games. It is for this reason that I am enamored with the creativity-enabling aspect of Minecraft. The recent Adventure Mode update only makes things better because now I can build an awesome map (in Creative Mode) and then release that map for players to explore in Adventure Mode.
I like world-building and adventure gaming and although Adventure Mode caters to both of my interests, I believe there are more ways which Mojang can improve upon their current designs.