User blog comment:Zambu/Useless passives/@comment-2094543-20130501151503/@comment-2094543-20130501232322

I agree, Xerath's passive is numerically fine, and you'll certainly be happy to have it if a Kha'Zix or Xin Zhao suddenly jumps you from across a wall, but it doesn't really fit his role.

Discouraging focus is pretty good for an artillery-type champion, but if your armour even becomes relevant, you're probably doomed already.

Ashe's passive hurts a lot in early game, but it's fairly ...unproportionate. It's just a guaranteed crit (okay, sounds good) with the application frequency of an ultimate (WHAT?). The fact that you charge it outside of combat means it won't help you more than once per fight, and you can't poke with it frequently either. One extra autoattack worth of damage every minute? Who cares.

Caitlyn can super-charge her passive with Runaan's Hurricane+brush, but before Runaan's existed, it was pathetic. (And I just read that the extra damage is unaffected by critical strikes - in that case you're absolutely right.)