The thought of this is pretty absurd. I just did Foundry, suffered a death at the hands of the Blacksmith, only to come back and defeat him, and my loot for the dungeon is imp guano and 5 mana crystals from one of the two chests. The other had nothing in it. I'm not asking to be rewarded with some super rare item for my time, but I do expect there to be something in these chests instead of practically nothing. Some decent sell loot at least.
The problem here is "what is enough"?
I agree that it feels bad to run a dungeon and get nothing at the end, but, obviously you can't get "good stuff" every time.
So what if you got a piece of Density armor? Is this still nothing?
To some people that's still nothing. It's not exciting, it's not rewarding.
It is "rare loot" though. So where is the limit?
My favorite suggestion that someone made on the forums here long ago was for the final fight or chest of each dungeon to drop a bauble that yields a few coppers. To me this seems reasonable.
Well, by sell loot, I mean items that shop well and have some return on coin, and this is at the very least. There shouldn't be great items in every chest, clearly, but 16gp for a fair bit of my time (and loss) is not the answer.
This same train of thought was applied to Bounty Boxes, and I believe it ruined them…this seems to be an example of everyone wanting a gold star for dying once in a cave….welcome to TRO.
I don't know what the bounty box argument was, but the way you describe it, I don't consider it even remotely the same thing. Bounty boxes are fairly common random drops that doesn't take any effort to get and they at least have something in them 100% of the time. Dungeon chests, specifically the ones locked behind the boss fight, should reward something for the time spent overcoming that challenge, and yet they seemingly don't. A good start would be the same amount of random gold a bounty box gives most of the time. I would go further and say every boss should at least have a chest behind them somewhere, and not in the same room. MinosPrime doesn't have one, I think he should. Tulor's Caverns has one in the same room, it should be beyond the boss and unable to be accessed until he is defeated - it might be scripted that way already in some cases, but a "treasure room" should be the reward for every dungeon, and there should be some random sell loot or gold reward for it most of the time.