Cause the main character is a stand user, it gives him the chance to run into other stand users and show by his example a good way to use their powers.
The show has characters from all walks of life, and its over the course of the show that we see good goals with the characters.
There are characters that, despite having a rough background, can change themselves through the actions they take.
I like how despite having a bloody past, Kenshin uses his fighting experience to help the community.
Despite having history as a soldier who killed others, Violet develops into a character who can empathize and help others.
Because of how the protagonist is able to get closer to the person who becomes like a mother to her, despite being cold and distanced.
Because as the main character comes to terms with his bad choices, he is able to overcome his failure in how he treated someone and changes his view on life, though it may not be as detailed as the manga.
Even when the protagonist struggles with an intent to kill others, just by meeting someone who believes in the best of her, she is given a chance to change.
Even though the main protagonist has a dark past, for the sake of others, he gave himself a new purpose, and even changed another character.
Although the main character was raised to be a perfect and obedient assassin, he met someone who changed his life for the better, although the anime isn't quite as good as the manga.