We definitely agree randomized levels have some key issues with them, but they are a big part of what makes a Diablo game, and how could we not have them? The Diablo franchise is built on randomization in all forms.

You bring up some good points though, but I don't think they're issues that are insurmountable.

Randomized levels can indeed create a very generic feeling if not done well. We're working really hard to ensure that doesn't happen though. It's actually one of the reasons why our exterior layouts aren't randomized. It's extremely difficult to have wide open areas be randomized as well as interesting. Instead we have static exterior zones where the roads, towns, and edges are always in the same place. To keep some bits of random in there though we have a bunch of small, medium, and large pieces cut out of them. In those cut out pieces the game can then place the randomized "adventure" sets. They could be artistic in nature (a fountain, an abandoned cart), they could spawn extra enemies, or they could spawn quests.

Our interiors are randomized, but we do some things differently that help make them more interesting. I think we accomplish this mostly by using our interior jigsaw pieces more intelligently, building more and different types of jigsaw pieces, and also because our artists are amazing. I don't think anywhere in Diablo III are you going to think "This place is not visually interesting". The types of interior pieces do make an enormous difference, and I think we're pretty good at it now. In Diablo II for example you pretty much had a few standard square set pieces, and then a bunch of hallways. We still have those in Diablo III but we're mixing it up a lot more with more intricate and interesting 'showcase' pieces that make it seem like they're not even randomized levels.

Anyway, that's all just something you have to see to believe.

Your other point was that randomization doesn't really matter because you're just essentially rushing from the start to the end. I think you're mixing in some specific Diablo II issues with randomization issues. Without hacks (like maphack) and some unhindered mobility skills (teleport), being able to just rush through the dungeons would be considerably hindered. So I think those are really non-issues when we're talking about a different game. They're things we have to be prepared for of course, but they don't mean that randomization is a waste of effort.

All that said there are a lot of things that you can do to entice a player to be invested in each and every trip into a dungeon. Rewarding them for exploration and perseverance. It could be something as simple as having chests spawn that the player actually cares about finding! (gasp) or something as complex as an entire game-wide system based around dungeon exploration. Either way or somewhere in between, we aren't looking to create a game where rushing from entrance to exit is the most rewarding way to play.