I don't. I don't consider it "well optimized" or "badly optimized" or anything in between. I simply don't have the information to make any informed judgement on that matter, and I doubt anyone else in this thread has.
"Optimization", as it's commonly used, is a matter of perception. The game could be doing cartwheels in the code, but if the result on screen is no better than a PS2 game visually and the performance is poor on high powered hardware, the perception is that it isn't optimized.
The screen could have cutting edge tech being displayed, but if it doesn't actually look better than something that takes less horsepower, it's unoptimized.
A 200k poly model that looks like a 2 million poly model is "optimized" better than a 2 million poly model that looks like a 2 million poly model.
No one is saying they can see the code. They are saying that the game sets a certain visual bar and it's not performing equivalently to other games that meet or exceed that bar (to them).
EDIT: not saying it's right, I'm just saying that's what optimized means to most people.