The concept of an adventure completely devoid of any reward whatsoever is one I have never heard of in any version of DnD I have ever experienced. You can make a compelling argument that DDO treasure tables are skewed too high, but arguing that xps were the only reason players undertook an adventure is simply not true. If you had a rogue character loot was usually the PRIMARY reason you bothered to leave the house. Many times parties were hired by wizards or clerics to find a valuable artifact.
Everyone always got excited about dividing the loot at the end of a module, and no one ever, ever came away empty handed. I guarantee a DM that pulled that, handing out a big fat goose egg after a module was completed would have been a very lonely DM.
If eaxh DDO quest is to be treated as a module, your words, then each quest should have some sort of actual reward, just like PnP modules do. There is Monty Haul DnD and there is random encounter treasure table DnD. I do not like either extreme much as they become boring. A well designed adventure has fun, a good story, challenging monsters, AND physical rewards such as gems, gold, and magic items.
In my opinion the loot rules should be one gauranteed end chest OR end reward (player/group leader choice) per adventure, a gauranteed end reward for any chain, AND a 10% chance to loot each optional chest.