Why are Spellcasters not as well liked as Vampires/Werewolves?

I think partly it is due to that we don't have as much as an in-depth tier for them.
Another thing I think it is because they tend to blend in with other Sims.
That said, a majority of my Sims are actually spell casters, and I purposely have them use wands, brooms, and familiars. I do that to bring them more into my game.
I also love werewolves and vampires, but there aren't as much yet in my game.