Problem with having "proper" dungeons that have twists and turns and alternate paths is that the most efficient and time saving path will be found and made mandatory by the community. "So what if you made rewards for going down those alternate paths?" Well, again, the shortest path to those bonuses would be found and enforced. "What if randomize where the bonuses are." Cost/time analysis will be done to find out the spawn points that are most efficient to check for bonuses. Any spawn points that would be considered too "off the path" to be considered worth getting would be ignored in favor of whatever rewards you get for just beating the dungeon. But...let's say theoretically they're able to make a "proper dungeon" completely balanced where you want to go down every side path to be able to reap the fullest rewards. Again, people will find the most efficient way to do so, any and deviation from the way will be mandatory. At the end of the day, if the designers don't make the dungeon a hallway, the community themselves will do it. The community, as much as some may claim otherwise, YEARNS for the hallway. Besides, it really kills the sense of exploration and discovery if you're combing the same entire dungeon, every single day, every single time.

There is only one piece of content that may be able to provide a sense of discovery every time you run it and make it worthwhile to explore every nook and cranny. Deep Dungeon. With its randomly generated floors and randomly placed encounters and loot, it is, of course, the most popular of content.... ... ...oh.

In seriousness, I think that it would be the best to encourage exploration and discovery, but it would need a serious upgrade from "all these boxes make a bigger box" room generation it has now to something a bit more robust.