The great part of this game is that you can skip some areas. Hissing Waste is more about collecting stories and codex's.
"You must find five maps which will each lead you to a tomb that holds a key fragment. The key fragments, once all are collected, will give you access to your ultimate destination, the Tomb of Fairel. " Along with the treasure hunt you get the story of Fairel's two sons.
Oasis Map is about hunting shards.
You don't have to do them if you don't want to. The game was designed for flexibility. Not everyone wants to find all the shards so they can skip the whole area.
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I find it odd that if you give the player more control of where they go next, they complain about it. The more options the better.
For me, it's such a jarring change from the previous two games in the series, and the change isn't a welcome one. I didn't play DAO and DA2 and say, "wow I enjoyed playing those games but you know what? I'd rather have more of a Skyrim experience. Instead of actually playing Skyrim, I'd rather have the next game in a series I enjoy deviate substantially from why I enjoy the series and try to emulate Skyrim."
It's not a bad thing to have completely optional maps, even some hidden areas which are a reward for exploration and don't have relevance to the main plot. But as people have pointed out, when only three out of the ten full maps are necessary to the story, the rest of the playable world seems extraneous. And people have pointed out how it would have been very easy to connect the zones to the main game, with the EP and Graves being necessary prior to WEWH or Arbor Wilds. The intention of the devs seems to be focused more on exploration than the actual story here.
ETA: I am hopeful that the devs see this. All three DLCs have taken feedback into consideration, in one way or another. JOH integrated a stronger central zone storyline to the new map. Descent still had beautiful scenery but tightened the focus, even though the story was weak. Trespasser had small, controlled zones but more companion reactivity and interaction. These are the kinds of things much of the base game is missing.