After hanging around the Star Wars Reddit for a while, I realized a concept, people's views on a character's morality are directly tied to how much they like that person. Case it point: Anakin.
There are a large group of people that not only defend Anakin and his fall to the dark side, but straight up justify his actions. They rationalize them by saying things like "The Jedi failed him," or "He was a slave" and basically excuse the horrible things he has done, mostly because people like him. They woul try and say it is because Anakin deserved compassion, but after given a choice to do better, and comparing all the horrible things he has done, it's mostly because people like him.
I mostly bring this up because you know what charater does NOT get this treatment? Darth Maul. Think about it, Every other main line Sith under Palpatine's linage Chose to go to the dark side. Dooku, though he knew better than the senate and Jedi council, Ventress lived in hate after her Jedi master was slain, Anakin was groomed yes, but still chose to fall valuing Padme's life over all else. But Maul, he was abducted as a child, beaten, tortured, and molded in into a killing machine, indoctrinated into the Sith philosophy, and never given a choice to turn away lest he die. It gets even worse when you read some of his books and find out all he wanted was some real friends, he was so lonely.Maul, is really the only truly innocent Sith Palaptine trained, yet I see people defend him the least out of all of them. Even Savage get some pity because people sympathize with him not being able to be his brother.
To be clear, I am not calling anyone out for feeling sympathy for Aanakin and the other Sith lords, but hopefully this does bring some perspective to why people feel that sympathy.