Yeah the climax of TDK could’ve been a lot better, but the same can be said for the Batman. I found the Riddlers master plan to be “awesome” too up until the flooding of Gotham bit at the end. That felt really forced. He finally got what he wanted and exposed the deep corruption in Gotham and then instead of targetting the corrupt he tries to kill everyone…? The entire third act fell flat for me. I still enjoyed the movie as a whole.
I agree with this. The entire climax/Act 3 felt very forced and tacked on. For me, in my personal head-canon, the movie ends when Batman confronts Riddler in Arkham and learns that Nashton doesn't really know Batman IS Bruce Wayne (or so we think).