[@Cio]

Because the title was given to over a thousand years prior to modern day, and due to how religion and other trends decline, so did the respect and fame they had in hell. Hence, the titles have become worthless in the eyes of demons.

EDIT: Essentially, the demons, like humans, follow trends just like we do. And when one loses it's fervor, another takes it's place, but it's still there. The sins are no longer regarded in the modern world, and new evils take their place, but they are still there.

Like old actors and celebrities.