Why do you think Majora's Mask 3D took so long?

[SJReiter]

I've wondered this as well. When I heard development began right after OoT 3D came out, I thought there'd be major changes, like new dungeons and side quests, but that's not the case. Based on the changes they did make to the original, I'm really not sure why it took almost 4 years to make.