The Sword of Damocles
The first indication that the show was in trouble was when NBC did not make a episode order beyond their original 13 to 21 or 22, like they did with The Blacklist during its first season.
The second indication was that the decision-makers kept pushing back when they would make a final decision on the renewal. My guess: the shot-callers applied a simple equation to the situation: how much money does the show bring in versus how much does the show cost? If the show brings in less than it costs, and gets bad ratings, cut it. If the show brings in less than it costs and gets mediocre-to-favorable reviews, consider a renewal. If the show brings in less than it costs with good review, renew, and watch closely for review / ratings change next season. My guess: the second scenario occurred with Constantine.
I personally didn’t watch the show because of changes they made to the main character. I didn’t watch the pilot episode, though some at FilmBook did. Others became ardent fans of the series. Some loved the show, what it had to offer, and will find the cancellation as bitter news.
In January 2015, NBC Chairman Robert Greenblatt, said “We got in the comic books bandwagon. Maybe there are too many of them.” Proliferation of comic book properties on the small screen was not a factor in Constantine‘s demise. Constantine being on NBC was the main reason for Constantine‘s demise. There is certain content that NBC can get away with showing and certain content it can’t get away with showing. This is the reason Frank Darabont didn’t bring The Walking Dead to NBC: NBC wanted the show’s producers to tone down the violence (a gargantuan blunder on their part e.g. that shows ratings and fanbase are the biggest on television and its storytelling is excellent. Now NBC does allow large amounts of violence through weekly episodes of Hannibal but The Walking Dead ship has sailed).
In toning-down Constantine, his deleterious habits, and his sexual proclivities, they killed what made him unique or at least hamstrung him thus the show, since he was its central character.
Matt Ryan Smoking Constantine Rage of Caliban
Do you think Preacher will make that mistake? On AMC? Not a chance. Its writers picked the right station for that material. NBC was the wrong station for Constantine. They sanitized Constantine instead keeping him raw.
Comic Roots and Lack of Crossover
Television shows like Daredevil, Arrow, and Smallville stayed true to the fundamentals of their characters, their comic roots, and succeeded because of it. Agents of S.H.I.E.L.D. succeeded because of the lead-in from The Avengers and other Marvel films that proceeded the premiere of its first episode. The Agent Coulson connection helped and the fact that movie actors have reprized their roles on the show. The show is an outlet for Marvel character junkies.
That connection and audience crossover will only increase as Phase 2 completes and Phase 3 of the Marvel Cinemantic Universe begins.
Constantine had no crossover audience from films. Keanu Reeves played Constantine in the big screen version and Matt Ryan played him in the television incarnation.
DC Comics has made the dubious decision not have crossovers between its TV universe and its film universe. No actor that plays a character on the small screen will play him on the big screen and vice versa. That decision was short-sighted (though they did see the light and offered Liam Neeson the opportunity to reprise his role of Ra’s al Ghul on Arrow).
Constantine was the first casualty of that decision.
I have no idea if Reeves would have taken the Constantine TV role or even if he was really a good fit for the role in the first place. His star power, fans, social presence, and the people that like his Constantine would have helped the NBC show, possibly enough for better ratings (or at least improved ratings) and a renewal.
What happened to Constantine was unfortunate but is also a learning experience for NBC and other stations that would bring a comic book to the small screen. Stay true and pick the right comic book to adapt for your station and its audience.
Smoke ’em if you got ’em.