You are basically saying as long as someone makes you feel really really sad and angry, that it gives you license to do torturous things to people. Sorry...that's not how justice works.
Not at all. If someone does something to you that pushes you into a psychotic break, and you hurt other people without being aware of it while out of your rational mind, you bear reduced culpability.
You're still responsible for harm, but less so.
If we're going to talk about justice, mens rea (the intention or knowledge of wrongdoing that constitutes part of a crime, as opposed to the action or conduct of the accused) is an important factor in both ethical and legal judgements.
In the show, Wanda is shown to be unaware of the harm she's causing to the townsfolk until the very end. She is first apparently unaware that she's doing anything to them at all, and when discordances in her idyllic TV world (reverting to the comforting tropes of her childhood) arise, she pushes them back down, suppressing her own awareness. When she becomes aware of the full scope of what she's done, and that the victims are in fact aware and experiencing her control and the town as torturous, she expresses shock and horror. And she does sacrifice her family, to the extent that she had them, to undo the ongoing harm. A family that clearly has SOME real existence within the boundaries of the Hex, as Vision's independence of mind makes very clear. They're not mere illusions and pure puppets of her will, though she does repeatedly pull Vision's strings and try to smooth over inconsistencies and breaks in his willingness to conform to her fantasy scenario.
This is in contrast to Agatha and Director Hayward, who are both consciously aware of the harm they cause. Agatha apparently also finding sadistic fun in it, and Hayward having some mix of selfish satisfaction and rationalization that his quest for power and abuse of Wanda are for the greater good. Both being motivated primarily by the acquisition of power and undeterred by the harm they know they're causing.
Again getting back to justice, I think everyone defending Wanda has acknowledged that she still bears some responsibility for the harm, and to set things right if she can, but the townsfolk made clear that they didn't want anything to do with her. If you've harmed someone, ethics demand that they get to say whether they accept any apology or act of restitution. At the end, the actual heroes of the story, Monica, Vision, Jimmy and Darcy, are unable to enforce any kind of punitive consequence on her or force her to get therapy, though they still probably have an incomplete picture of all that's happened. Monica acknowledges Wanda's sacrifice, probably hoping that Wanda will be able to overcome her trauma and be a hero again, but unable to do anything more to aid that. And none of them are aware of the Darkhold or what it's going to do.