'Why can't anyone make a decision?' My first time as a D&D Dungeon Master

Four bedraggled adventurers stand together on the shore of a desolate island, shivering in the evening mist. They don't know each other, and their motives for being here are unclear. But as they make stilted conversation they see, emerging from the briny waters, figures dressed in the rags of sailor outfits, moaning and shuffling and horrible. The adventurers stand around, roll some dice and chat some more, as the undead seamen lurch ever closer. Looking on at this desperate scene, I think to myself, "What the hell? Why can't anyone make a decision? We've been here for half an hour! We've not even begun the proper adventure yet!" Dungeons and Dragons has always been there in the background of my life.