^ I think that's because, for a lot of people, the game just wasn't satisfying enough. I think some are looking to the DLC content to fulfill their villain & boss fight needs that were missing from the main game.
I unfortunately have to agree that the game was severely lacking in villains & boss fights. The only boss fights we had either involved the Batmobile or were cut-scenes. The Batmobile boss fights might not have been so bad had we only encountered that type of fight once or twice in the game, but we had tank fights thrown at us left right and center - so it got repetitive fast.
We were told we'd be getting villains teaming up to take down Batman, but we didn't get that at all. I was hoping for villain team ups, but nope. Halfway through the game I was thinking to myself "where the hell are the villains?". You
have to do the side missions to see any of them, and to me that distracts from the main story which is the one that has the urgency. It's not natural to pursue those when you're following the path of the main narrative.
Also, the side mission villains were severely underused.
The Man-Bat mission is the worst offender. Rocksteady know how much people have wanted him in the game, and what we got was a slap in the face. I honestly thought, when they announced we could use weapons in flight, that they'd added that for aerial boss fights with Man-Bat and Firefly. But as it turns out, you don't need that function at all really and the Man-Bat fight was all cut-scene. They could've at least made him faster so you had to chase him through the city. They did give us that faster flight and boost capability after all.
I sadly feel that this game was lacking in a few other areas too, and was mostly story driven without a satisfying conclusion.
With Arkham Asylum and Arkham City, as soon as I finished the main story I couldn't wait to start over again. But with Arkham Knight I don't have that feeling. That's not to say I didn't enjoy it at all, some parts were fantastic - but it mostly fell flat for me with too many unanswered questions and too many plot holes. Oh, and too much Batmobile. If it were just a means of transport to get around the city, with the
occasional chase/boss fight, I think people would be praising that feature a hell of a lot more.
Another thing that irks me about the Batmobile is the way it handles. It just doesn't feel like Batman. I know the city is deserted, but Batman has the skill to drive at high speed and
not crash into walls/cars/objects, so that's what he would do. He causes more damage than the rioters! Even after you're used to the driving after a while, it's still hard not to crash into
something and for me it just doesn't feel like Batman.
Anyway, hopefully the DLC will give us those much needed villain boss fight/predator room scenarios that were sadly missing from the game.