I think map and mode rotation are completely pointless. Let people play the modes they want to. If people don't play a specific mode much, that just means next game you either change it or ditch it. You don't get that kind of player number feedback when you limit the available modes.
The same idea goes for map rotation. How do you know if players have preferences for specific maps with particular designs if you can't measure full player numbers choosing specific maps? When you limit the number available, you're basically saying "screw you, we don't care if you don't like any of our map designs". CoD has done it perfectly, and there should be no shame in adopting the model of giving choice to players.
During the Black Ops 3 beta, I could not have been unhappier stuck in the same rotation of three maps, and later four. I could excuse it though because it was a beta with a limited number of maps. That's okay. At this point, Splatoon needs to seriously update to make player choice a point of greater impact in future designs.
