The DCEU has plenty of characters the fans love and are always happy to see. But for every Wonder Woman, Aquaman, or Harley Quinn, there are also a lot of characters the audience isn't all that excited about. Some of them luckily played only a small part in the movies, but others have had a bigger impact on the DCEU as a whole.
Not all of those characters are badly written, though. Some of them fulfill their function perfectly. However, because of what they do or how they behave or treat others, it's really hard to like them. And then some characters are just plain bad.
The Joker
After Mark Hamill's animated Joker and Heath Ledger's performance, the expectations for the character were high. But Jared Leto's Joker turned out to be very lackluster in the Suicide Squad (2016).
This version of the Joker was just a mad maniac and he had nothing of the strength and charisma he possesses in the comics. Maybe it was because Joker had only a limited space in the film, but also because he was portrayed as a rather one-dimensional figure. That made it very hard to sympathize with him.
Ares
When Ares finally shows up in his real form in Wonder Woman (2017), it should have been an awe-inspiring moment. Instead, the more memorable villains of the film were general Ludendorff and especially Doctor Poison.
David Thewlis is an excellent British actor, but while his Sir Patrick looked like a sympathetic guy, the same can't be said about Ares, who comes across as a standard run-of-the-mill villain despite his formidable powers.
General Ludendorff
Speaking of General Ludendorff, he also won't be winning popularity contests anytime soon. But that's not Danny Huston's fault. The character of Ludendorff is simply written as highly unlikable.
Ludendorff has no respect for human lives and he's willing to sacrifice many people as long as it fits his purpose. He's a cruel fanatic, and very few fans will like someone like that.
Lex Luthor
Lex Luthor is one of the best comic book villains. Smart, determined, cunning, and manipulative, Luthor rarely ever loses his calm. And his comic book persona has very little in common with the DCEU version.
For most of his time on screen, this Lex Luthor acts like a spoiled and rambling young man whose evil plan works out by a sheer miracle - because it has so many logical flaws. Needless to say, the actor Jesse Eisenberg has many more better-accepted performances by the fans, as this character and casting was just a flop.
Jimmy Olsen
Just like Lex Luthor, Jimmy Olsen in the DCEU is very different from his comic book persona. So much so many fans even didn't initially realize who they were looking at when Jimmy popped up in Batman v. Superman: Dawn of Justice (2016).
Not only was his character and behavior changed, but his role was also cut drastically short when he died soon after he appeared in the film. Unlike in the comics where Jimmy was goofy and lovable, this Jimmy had no opportunity to get the fans' sympathies.
Amanda Waller
Everybody knows that Amanda Waller is the one who puts the Suicide Squad together. But while her intentions might be good, overall, Waller herself isn't so sympathetic.
In the comics, Waller is humanized a bit, but in the film, she looks like a person nobody would want to interact with, let alone be friends with. When the villains turn out to be more sympathetic than the supposed good guy, it's clear there's something wrong.
Marylin Batson
Marylin Batson, Billy's biological mother, only appeared briefly in Shazam! (2018) but she still managed to leave an impression on the audience. Unfortunately not a good one.
When Billy finally finds his mom after he's been looking for her for years, he learns that she wants nothing to do with him. That's a crushing moment for the young boy and also one of the reasons why Marylin won't win any mother of the year prizes.
Hunter Griggs
It looks like the Suicide Squad has many unlikable characters, and Hunter Griggs is one of them. Griggs guards the Suicide Squad in their prison. He's most often seen interacting with Harley Quinn.
His behavior toward her makes it clear that Griggs isn't a good guy. Just because he was on the side of the law, it didn't mean he was likable and the fans often took Harley's side despite the fact that she should have been the bad guy and he should have been the good one.
Orm
It's no wonder that Orm isn't popular in the DCEU. He served as the main antagonist to his half-brother Arthur and was willing to kill Arthur to get what he wanted.
It's true that Orm was upset by the presumed death of his mom but that doesn't change the fact he also wanted to wage a war with the rest of the world. Overall, even though he seemed to have made amends, in the end, Orm was never going to be as well-accepted as Arthur himself.
Cheetah
Before she turned into Cheetah, Barbara Minerva was sympathetic, sweet, and kind. But her wish twisted her personality, took out all of her kindness. Cheetah would never stop going after Diana, fueled by her rage. Even Maxwell Lord realized the error of his ways in the end, but Cheetah didn't.
She only stopped fighting when it looked like she lost her powers. But it's more than possible she'll appear in the DCEU again to cause even more trouble for Wonder Woman.