More killers should have passive abilities

Right now, and if Im not mistaken, 2 out of the 26 killers have passive abilities. Spirit with her passive phasing and Nemesis with zombies. Most of the times these aren't game changing features but do help make the killer feel a bit more powerful. So why wasn't this implemented more? I mean, it's weird that they decided to go for a passive ability with the Spirit considering how strong she is, but decided to remove cloacked bloodhound on Wraith, it doesn't really make much sense to me.

I think the devs should start adding passive abilities specially to weaker killers like Clown or Pig. Of course it wouldn't have to be something oppresive or creative like the zombies, but some lore accurate stuff like passive phasing on the Spirit, or basekit bloodhound to Wraith would greatly benefit these characters. And I don't think they would even be hard to balance to be honest.