People didn't quit because they played URF. People like URF because it's fast and stupid and breaks pace with the monotony of the game. The game was fine as it was previously, but each year Rito just kept pushing for the casual audience. This is incredibly stupid on their part because they already had a majority of players playing either way. People quit because Rito fails to see that they aren't helping the game in any way shape or form outside of making it more appealing to casual players. These players are your typical "I play X mainstream console game made to sell to masses so much, like, I'm totally a hardcore gamer" type of people.
TLDR; Rito is giving it's previous loyal player base the big ole bird and shaft while trying to coddle and win over a degenerate mass that couldn't care less and wouldn't bother playing for longer than 15 minutes.