8 Reasons Gotham's Second Season Could Fail Miserably
3. Predetermined Futures Lessen The Threat To Main Characters
Almost as detrimental to Gotham as realizing how old some of the villains will be by the time Bruce becomes Batman is the knowledge of characters' future, potentially lessening almost every threat.
Again, shows have taken familiar characters on different paths. Gotham actually killed off Sal Maroni long before he is supposed to help turn Harvey Dent into Two-Face, but think too hard and too many villains seem like they're holding back and biding time.
Star Wars tread these waters with Lucas' divisive prequel trilogy, paralleling the story of Anakin Skywalker's journey from good to evil with the Old Republic's similar journey under a string of corrupt and ineffectual leaders culminating in the rise of Emperor Palpatine and the Galactic Empire. The difference is that no matter what is added to it or when, Star Wars is one long story. Even if you distinguish between the plots and subplots of the various movies, their inter-connectivity makes it dangerous to the telling of that overall tale to leave any one of those story lines out.
Gotham is one city with any number of different characters, stories, and threats which, were it real, could have different outcomes. With Gordon presented as the reliable cop we've always known, the problem worsens by limiting how much he can be grow and be changed by the series' events and its other characters.