I really think it's wrong to say those things are terrible as opposed to mediocre, though.
This is going to boil down to a matter of opinion, but I stand by my statement. If any one of the elements in the game, from the combat to stealth, etc. was put into a smaller game, that game would have been universally reviled. The only reason any of it can be excused is that the game does EVERYTHING.
I think it's important to acknowledge the interesting and important things that DX did, from successfully making an FPS RPG to allowing players to (almost) go the entire game without killing anyone and allowing multiple ways through the levels, but all of the separate systems were absolutely crap. The game itself is better than the sum of its parts, but that doesn't mean I'm going to excuse any of the parts.
~Jason