Why GGG can nerf Arsonists last season but cant nerf LS now?

Last season they nerf skeletal arsonists, SRS and grim feast without any embarrassment. Even though it wasn't nearly as imbalanced as LS. They themselves admit that LS does not work as intended but do nothing. This is some kind of nonsense, in some cases it is acceptable for them to nerf builds that a lot of people play, in other cases for some reason it is not, although these damn arsonists were just an OK build, nothing special.