With Zack Snyder's time at DC Films apparently over and the DCEU semi-abandoning the shared universe model, any discussions of Snyder's discarded future plans are all academic. Still, one under-discussed, background choice of Snyder's was actually one of his greatest mistakes.
With the allusions to a dead Robin slain by the Joker in Batman V Superman, most assumed the past Boy Wonder was the second Robin, Jason Todd, murdered as he was in the comic "A Death In The Family." Then Snyder revealed, no, his intent was for this to be the first Robin, Dick Grayson. Even some of the Snyder faithful questioned this, and rightfully so. Changes in adaptation are necessary, but they should be done in service of improving the story. Making Dick the dead Robin instead of Jason not only wouldn't have improved the DCEU, it would've actively made it worse.
10 It Effectively Nixed Any Hope Of Seeing Nightwing
Dick may have been introduced as Robin, but it's been decades since he's been a Boy Wonder. Nowadays, he's a solo act that goes by Nightwing. From both a commercial and a storytelling standpoint, including Nightwing in a DC Cinematic Universe is a no-brainer, especially since the DCEU's Batman was introduced as having already been Batman for twenty years.
This meant Dick could've been introduced as Nightwing right off the bat, with no need to chronicle his time as Robin or falling out with Bruce outside of cursory backstory. Of course, killing off Dick preemptively prevents anything from being done with Nightwing.
9 It Complicated The Possibility Of Adapting "Under The Red Hood"
By combining Dick and Jason, the DCEU also robbed itself of the potential to tell the most famous story about Jason Todd: His resurrection and attempted revenge on Batman in "Under The Red Hood." Now, a version of the Red Hood story could've been done with Dick as the revenant Robin, but why bother even making the dead Robin Dick just to turn around and make him Jason in all but name?
The DCEU Batman has also shown willingness to kill, which would've spoiled a potential adaptation for a different reason; the Red Hood's anger isn't because Bruce failed to save him, it's because Batman didn't avenge him.
8 It Instantly Reduced The Number Of Potential Bat-Family Members That Could've Been Introduced
Batman has accumulated a wider supporting cast of sidekicks, partners, and other costumed characters than almost any other superhero. Indeed, the "Bat-Family" has grown so large that Gotham City alone has enough characters and stories to sustain a shared cinematic setting all on its own, an intriguing prospect indeed.
Again, one of the benefits to starting off the DCEU with a veteran Batman was the chance to get the Bat-family rolling sooner rather than later. Since Snyder's plans were to take two of the most prominent Bat-Family members off the table from the outset, it seems that never crossed his mind or interest.
7 No Dick Grayson Basically Meant No Teen Titans
Another franchise that would've seemed an obvious pick for DCEU adaptation would've been the Teen Titans; the second most famous DC superhero team after the Justice League, composed of many of the League's sidekicks.
Dick has traditionally been one of the core members and often leader of the Titans; it was while on the team that he became Nightwing, and he was a lead in both the animated and live-action TV adaptations of the team. Attempting to bring them to the DCEU without him would result in a hole in the team.
6 It Wrongly Presumed That All The Robins Are The Same & Are Basically Interchangeable
The only thing Dick and Jason have in common is the initial premise behind their characters; young orphans adopted by Bruce Wayne who become Robin. Beyond that— especially after Jason's original copycat origin story was retconned post-Crisis— they have very different personalities and have taken very different paths, so different they could even be considered each other's foils.
Where Dick is affable, Jason is sardonic. Where Dick is heroic to his core, Jason is much more brutal. Whereas Dick is probably the most mentally healthy member of the Bat-Family, Jason is probably the least. Assuming the characters are at all similar just because they both once wore the same costume is a surface-level reading at best.
5 It Echoed One Of The Worst Aspects Of Frank Miller's Batman Universe: His Dismissal Of & Vendetta Against Dick Grayson
Frank Miller's Batman is easily the greatest inspiration for Snyder's; perhaps Snyder's plan for Dick's death was a way of honoring Miller's long history of screwing over Dick. Dick is absent barring the occasional mention in The Dark Knight Returns, having had a falling out with Bruce so bad that he doesn't even show up to his mentor's funeral. The full extent is revealed in The Dark Knight Strikes Again, wherein Dick has become a new Joker and is killed by the story's end.
Miller continued this with All-Star Batman & Robin, The Boy Wonder, his take on the origin of Dick Grayson at age 12. Batman in ASBAR is a full-blown psychopath who subjects Dick to abuse so awful it's almost comical (much like ASBAR as a whole).
4 Batman Allowing Joker To Live After Killing Dick Makes No Sense
One defense that has been marshaled is that only the loss of his first (and, let's be real, favorite) son could turn Bruce into the man he is in Batman V Superman, one who has forsaken his code against lethal force.
However, that opens a whole other can of worms; if this Batman kills, and does so because the Joker killed Robin, then how is the Joker even still alive? Adding to the confusion is how Batman promises to the Joker's face that he will kill him during a flash-forward in Zack Snyder's Justice League, so why hasn't he done so already?
3 Batman Has No Greatest Success To Counterbalance His Greatest Failure
It's often said that Dick is Batman's greatest success, while Jason is his greatest failure. One of the best demonstrations of the former is in Young Justice episode "Agendas." Questioned by Wonder Woman over the ethics of bringing a child into a war, Batman protests that Dick needed to find justice for his parents' murder. "So that he could turn out like you?" Diana asks. Bruce's response? "So that he wouldn't."
With DCEU Dick being the one and only Robin and also dead, there's nothing to counterbalance the failure of Batman to save his son. Complaints about Snyder's approach to DC's heroes being too dark and depressing is well-tread ground that doesn't merit another deep-dive, but this is just another example of why people might feel that way.
2 Setting Up Carrie Kelley To Be The DCEU's First On-Screen Robin Was A Strange Plan, To Say The Least
Snyder doesn't seem to be a fan of Batman so much as he's a fan of The Dark Knight Returns. A perfectly defensible position, but it's also the root of his approach to handling Batman and the problems some have had with that handling. Snyder's plan was to, at some point, introduce Carrie Kelley from TDKR as the second DCEU Robin.
Carrie is a perfectly fine character, but compared to other sidekicks with much deeper history and character development, from Tim Drake to Stephanie Brown, Barbara Gordon, Cassandra Cain, and yes, to Dick and Jason, she just doesn't stack up. Snyder's desire to include her is more evidence that he would've been better served as the director of a stand-alone The Dark Knight Returns feature, rather than the architect for an entire cinematic universe.
1 Snyder's Own Plans For A Second Batman Movie Further Diluted Dick Grayson's Legacy
Snyder's planned conclusion for Bruce's journey, sacrificing his life to defeat Darkseid, calls to mind Grant Morrison's "Final Crisis." In the comics, after this event, Dick assumed the cowl and became the new Batman. Snyder's plans, however, were for Bruce and Lois Lane to conceive a child, raised by Lois and Clark, to become the new Batman in a "20 years later" epilogue to "Justice League 2A."
So, in summation, here are the two ideas for "Batman II" compared: Bat-love-child versus a kindred spirit of Bruce’s, trained by the man himself and without the flaws that bogged Bruce for his whole life. It's pretty clear what's the more satisfying story.