It is kind to the villains in some ways, but often it seems not to let them reverse the mistakes they made. For example, Wang Xiangyang dies and cannot reverse the Merit Brush spell that releases Ye Zun. Sha Ya gets sent to Dixing (and eventually eaten by Ye Zun) without being able to change Ye Zun's plan. It's more like, okay, you realized the horrible error you made, now you and everyone else has to deal with the consequences.

Having Ye Zun redeem himself would be a twist on it, true, but to me that seems more of a cop-out "we want a happy ending" as opposed to exploring the theme they have built up and the consequences of it.