Joker's decision to keep Batman's true identity a secret is rooted in the delicate balance that defines the relationship between Batman and the Joker. The Joker understands that exposing Batman's true identity could jeopardize the unique dynamic they share, a dynamic that he cherishes above all else.
However, his ultimate goal was to mess with Batman, not to reveal his identity. The Joker went to extreme lengths, like threatening to blow up a hospital, to prevent anyone else from exposing Batman's identity. This shows that he didn't want anyone else to have the satisfaction of revealing who Batman really was.
Batman's mask is desgined to protect itself in most of his costumes. It has different defenses, the main one is a powerful electric shock if somebody tries to remove it.
The Joker didn't want Batman's identity for any reason but as a way to say that he has beat the system. He threatened to kill people in order to get Batman to do what he wanted to. If he could do that, he would prove that chaos beats order.
The classic answer as to why a secret identity is to protect the people in your life from reprisals. With Batman, think of it this way. ... Let the chaos begin—he'll likely be arrested, will be unable to be Batman again, may have his company voted out from under him, assuming the value does not hit bottom.
While it was teased that The Batman's Riddler knew Bruce was Batman, it was eventually revealed that he hadn't uncovered the truth as his comics counterpart had. Likewise, Deathstroke, Bane, and Joker all know Batman's secret, as well as Ra's al Ghul and his daughter Taila (the mother of Bruce's son Damian).
While it becomes clear that the Riddler didn't actually know Batman's identity, he certainly came closer than anyone else to cracking the mystery. The clues to uncover Batman's secret were right in front of him. The Riddler sends a package to Wayne Manor with the expectation that Bruce will open it.
Narratively, he got a permanent smile scarred into his face just by being born, which is tragic. But cinematically, the idea came from the 1928 silent movie that inspired the character's creation in the first place, The Man Who Laughs (the link to The Batman Who Laughs is clear).
It implied that there was always more than one Clown Prince of Crime. It seemed that one of The Jokers actually created the other two! Unfortunately, it never revealed which was which. What it did reveal is that Batman has actually always known the real name of The Joker.
Following the suspicious death of his multi-millionaire parents, Sionis had inherited their fortune and went on to bankrupt their company. Saved by a buyout by Bruce Wayne, Sionis came to resent and hate Wayne.
Black Mask then continues to threaten the most important people in Catwoman's life, prompting her to retaliate by shooting Black Mask's jaw with her gun, killing him. After the shooting, Selina Kyle passes the mantle of Catwoman to her friend Holly, who is soon arrested for Sionis' murder.
Batman's already covered most of his face, so a full-face mask wouldn't be a huge improvement. He keeps his mouth uncovered for several reasons: It lets him quickly don gas masks and rebreathers. It reassures children and other civilians when he talks to them.
He admits that for a while he did think Harvey Dent was Batman, knowing that Dent and Rachel were a couple and seeing the way Batman threw himself out a window to save Rachel (while he eventually realized Dent wasn't Batman, this did make him realize that whoever Batman was, he also cared a great deal for Rachel, ...
While Harley Quinn discovered Batman's secret identity long after the Joker involuntarily learned the truth, DC's first Harley Quinn found out Batman was actually Bruce Wayne decades before either of them–and did so after her first time meeting the Caped Crusader.
Why does Batman always see Joker in Arkham Knight?
In Batman: Arkham Knight why did Batman see Joker even though he took the cure in Arkham City? The explanation given is that he cured himself of the Titan poisoning but he still had Joker's blood in his system so that combined with the fear gas made him see Joker.
The psychopathology Arthur exhibits is unclear, preventing diagnosis of psychotic disorder or schizophrenia; the unusual combination of symptoms suggests a complex mix of features of certain personality traits, namely psychopathy and narcissism (he meets DSM-5 criteria for narcissistic personality disorder).
Related: How Did The Joker Actually Get His Scars? The Joker's true reason for telling different stories is to empathize; not with his wife, but to relate to whichever victim was about to get his blade in their cheek. He sizes them up, tells them a story he could see them in, and then gives them scars to match his own.
Joker remains one of the evilest bad guys in all DC, but there have been a few times in history that he has done good things, and even acted heroic. One thing that has always defined Joker in DC comics, movies, and TV shows, is that he is not a good person.
It was shown that despite having cured himself in Arkham City, Batman was still infected by the events of Arkham Knight — considering that Batman only took half the cure and intended to give Joker the other half it could be assumed that was not enough to completely cure him in the long run and was only intended to save ...
Batman: Three Jokers #1 (August 2020). In Batman's origin story, Joe Chill is the mugger who murders young Bruce Wayne's parents, Dr. Thomas Wayne and Martha Wayne. The murder traumatizes Bruce, inspiring his vow to avenge their deaths by fighting crime in Gotham City as the vigilante Batman.
The Riddler had a grudge against the Waynes having lived in their squalid orphanage as a wee 'un, but seeing as they were already bumped off, and resenting the sympathy he reckons Bruce got but which he was always denied, he went after Bruce. Warner Bros.
