There are many players that enjoy games because they can 100% the game, and not only because the achievements inside of the game, but the achievements in the steam profile, there are many posibilities for the achievements, like "Collect all the gallery images", "discover a cool easter egg", maybe the same achievements in the game can be added in steam achievements.

Maybe this wont be added til the game be finished, because the team have their priorities, its understandable, but it is a cool add that can be cool see in the game.