URF Changes

While URF is one of the best modes to play in League because it's fast pace and overall more enjoyable than the actual game, there are a few things that ruin the fun of the game. Riot should really implement a Diminishing Returns effect like WoW has for their PvP with CC effects, especially for the CCs that are longer than their CD or are close enough that they can keep you CC the entire fight. Examples are Fiddle's fear, Rammus' taunt, Morgana's Q is close enough, Pantheon's W, Ahri's Charm to name a few. There should also be some changes to champions passives in that mode, the main one I'm looking at is Rumble's passive, how it's normally a double sided blade, it gives the spells bonuses but he can't cast for 6 seconds, with that being non-existent in URF Rumble is free to steamroll any team with dishing out massive amounts of damage, whilst taking minimum with his shield up every 2 seconds.

The mode is fun and a different pace than regular League, and I really enjoy when we have URF or One-For-All as a game mode, but why have rules in One for All (Teemo, Karthus, etc. perm banned) but not make any for URF?