Anyone pining for larger dungeons with multiple routes and such would do well to read the threads about speed runners in Palace of the Dead. Go into a matched party looking to explore and get silver chests, and see what happens. Sure, sometimes you'll be able to, but generally people play that content exactly one way, ignoring a large amount of the content that exists in it. This will always happen in dungeons. I would like sprawling dungeons full of exploration, too, but I know exactly how that will play out. Those dungeons will quickly be reduced to a linear corridor for speed runs. So that's what dungeons are now designed as, and they should be. To do more is going to waste dev time and cause fights among the player base.

Or, to put it more bluntly, you will never get what you want. If the devs try to give it to you, the players will take it away. You're only asking for disappointment.