The Dungeon Delve as Repatriation Quest

I love old-school dungeon crawls. I love the simplicity of the setup and the endless variations that can come out of it. I love treasure as a universal motivator for PCs. But more and more I'm feeling a bit uncomfortable with the colonialist aesthetic that goes along with the traditional dungeon delve. The basic assumption is that the dungeon environment exists to be exploited by the player characters. Denizens of the dungeon might be attacked, robbed or allied with, but ultimately these are all just different strategies to achieve the goal of extracting wealth. The morality of extraction is neither questioned nor explicitly asserted; it is simply how things are.

A lot of old-school groups thread this moral needle by just running with the theme that the player characters are not good people. If you can enjoy the anti-heroic exploits of Jack Vance's Cugel or Umberto Eco's Baudolino, then why not play out such stories in a roleplaying game?

I don't see anything wrong with this approach, but I'm wondering if we could play legitimately righteous characters in a dungeon crawl setting, if we were to turn the whole premise on its head.

Say that some colonial empire--interdimensional unseelie elves, perhaps--has been laying waste to the PCs' homeworld for centuries. They have stolen the great treasures of the PCs' culture and locked them away in a vast and cruel fortress that sits on a crack between worlds. In recent years the empire has fallen into ruin and internecine warfare. The fortress stands half-abandoned, half-occupied by a variety of opposing factions.

The PCs come from a culture living in a state of occlusion. Large portions of their history have been erased by violence. They venture into the fortress not only to repatriate the physical artefacts of their culture, but also to rediscover their lost past.

Along the way, they may encounter stolen treasures from other cultures in other worlds. Experience points are awarded not merely for seizing treasure, but for returning it to its rightful owners. XP value is not measured by sale price, but by historical and cultural significance.