User blog comment:Tails365/Current junglers/@comment-77.105.51.43-20130304224452

You answered your question yourself, those junglers that you mentioned are easy to play. Speaking of Amumu there is not easier jungler than him, just level up Tantrum, put some points in bladed armor mastery and you will be negiating quite a lot of damage plus the cooldown reduction from hits, and ganks... If you land the Q enemy is quite screwed because Amumu will just stick to him like glue.

On the other hand Udyr requires skill and does not have that button for destruction mode. Usually that is a skill that can do something very impressive, like Kha Zix's jump or Amumu's Bandage Toss.

People pick to win not to have fun so that is why you see Diana, Amumu and company a lot. And you forgot to mention Kha Zix.