Well, its dungeon crawling and fantasy RPGs are hardly strangers to that. I have no real problem with them in Origins and Awakening. The quest is long, but it has to be, because you're travelling in search of something lost ages ago. If you could trip over it over a few minutes, it wouldn't be much of a lost treasure, would it?
The biggest problem I have with that quest line is the implausible nature of it. I get that the Wardens can sense Darkspawn, and they themselves are immune to it, but the sheer volume of Darkspawn you kill it seems rather odd that your team members hold up so well against infection, especially given the up close and personal nature of many of their fighting styles. Like several of the other quests, I also have a big problem with you attempting this at all, because it seems like such a sucidal long shot (as does the Dalish Quest line traipsing through a magical forest of illusions, fighting against the Werewolves, who infect with a single deep wound for a cure that 'might' help the Elves, or heading up into the mountains in search of the Ashes, trusting that a religious miracle will occur when you find them etc etc.
Its not surprising that many of your team question your wisdom during these quests.