The hidden message of Joker

Rating: 9/10 (16 April 2020)

This review contains spoilers: Joker and Dark Night.
I have seen "Joker" a couple of times and I was wondering about the main idea behind the movie.
Arthur, played by amazing Joaquin Phoenix, is an unhappy character that lots of unfortunate occurrences were following him through his life. He eventually turns to Joker, one of the most dangerous and lunatic villains ever existed. How come that we fall in love with him and with Joker.
How come that a director, or a writer, or a producer, makes, and supports a movie in which you become a fan of evil. The greatest of all, The Joker!
Compared to Nolan's Dark Night, the other great movie in the Batman series, Joker is not an action movie. In Dark Night the hero, criminals, all supporting characters, and all the people in the movie face the dilemma at least once in the movie. We know that Nolan focuses on this kind of psychology through his movie. In contrast, in Joker it seems that there is no such a thing. Everything is so smooth like we are reading a newspaper. Reading a report on a psychological case: there was a kid that got abused by his mother in his childhood, as a result he is struggling for everything in his life, such as work, love, attention. He eventually grows self-hatred, results in seeking revenge on others, as he thinks they are a part of and the cause of his misery. It is more like a back story of future movies.
Arthur is so human, like us; day dreams about TV shows, kisses the attractive neighbor in his imagination, and sees himself as a good person when he talks to important people in his mind, as we all do the same.
We love him. He is a great actor. He impresses us the whole time. He is fantastic!
I asked myself, is it ethical to love a criminal? How come we become so attracted to this evil? Especially in the last scene, everyone hooray him, he stands on the car and everyone praises him, everyone loves him.
It seems so if we don't pay attention! It is not a movie which purifies evil and introduces a new hero! Now let's check the facts and understand what actually happens and reveal the real message with two questions:
1- Why do people start to wear clown masks right after Arthur kills three young men? Are they supporting a killer?

No, they don't. Thomas Wayne calls all low classes, and less fortunate ones as clowns and they get angry. It doesn't have anything to do with Arthur, as he thinks, but in fact it was just a social political twist: If you call someone mad, they go mad.

2- Why do people save Joker, after the car crash, after he confesses on TV and kills another man on a live show? Why do they praise him?

Another no, they don't praise him as a killer. When Arthur is on his way to Murray, we see clowns on the subway, on streets, and everywhere. The riot had already started when Joker was on the show. They've never watched the show, they didn't know Joker killed Murray. They find a clown in a crashed police car, right in the middle of the fight between police and clowns, and they save him, helping a protester fellow.

Which leads us to the most important message: in a chaotic situation, you don't know who you might support, you can save an angel or the devil himself.
I think Joker is not a social-psychological movie. It critically questions political decisions. If people don't have any voice, if they are not seen, they may unintentionally support and empower the wrong person.
It is a crime thriller movie when it is about Arthur, and it turns to horror from the social political point of view.