Thief should have been an AA game. When you make an AAA game you have to cater to the console crowd in order to stay afloat which means sacrificing a lot of the values the original game stood for. An AA game can still look good, even if less detailed but since you don't have to keep so many tastes in mind you can make the game closer to the original.
The game is a mess...and I don't usually say this about games. You can't even jump in it for christ's sake and the plot and atmosphere remind me of bad fanfic.
That said, the game looks amazing, if a bit overdetailed AND had moments when if truly felt like a Thief game like that Jeweler's shop. That part really was brilliant. There was this part with a safe and a sleeping guard. You had to creep slowly and pick the lock. Now if you failed at any stage of the lockpicking, the guard woke up. There was also a room right next to this with a guard patrolling and with lamps that couldn't be extinguished. This was the part with the most loot in the level. To do it quietly, you had to move from shadow to shadow and steal as fast as possible, before the guard got to you. Why wasn't the game more like this?!!!! Judging just by this short part of the game, I could tell that the devs were conflicted when making the game. I don't think it was the lack of talent, rather the realities of AAA game development. Had the budget of the game been something closer to an AA game, it would have been superior in all ways except graphics but since even OK graphics are realistic enough for today's games, as compared to say ok graphics from 2000-2003, it would not have been such a big deal. Today, an interesting art design is more important for me, graphics have become good enough. If games stopped looking better than TW3, DA:I or Battlefield 4, I wouldn't care.
So why is overdetailing bad? Well it's something I noticed while playing Thief 4 and I think it is a cause for linearity in modern First Person games.
In old games like Doom and Thief, the rooms were just simple, geometrical shapes with limited detail. This is an advantage because it is very easy to discern the important bits of a room, like a switch or a quest item. In Thief 4, the levels are SO detailed that it's hard to figure what's usable an what's not. I even got lost a few times, not because the levels were complex (they're really not) but because of all the detail. This is why the climbable surfaces had that "gamey" white paint on them. The developers knew that it would be hard to discern what is climbable and what is not. This is also why many games have guidance systems like markers or big flashy arrows.
NOW, I am what some would call a graphics whore so visuals help a lot with immersion for me but in a game like Thief, where individual objects have to be in sight, the visuals HAVE to be balanced in a way that they are both beautiful AND functional. The visuals should never get in the way of a First Person game with emphasis on exploration and this is why a game with lower production values would actually benefit the franchise more.
Again, the best modern Thief experience you can hope for today is The Dark Mod. If you pay attention, you can tell that the visuals were crafted in such a way that they don't get in the way of your game. They are both beautiful and functional. No matter how detailed a map was, like Tears of St. Lucia, I never got lost because of I couldn't discern what could be picked up, what could be climbed or didn't know which part of the level was accessible or not, I got lost because of how sprawling the level was.
"This claw will get you killed"... And than we use the damn claw the whole damn game. 
