if they make a couple changes here, people will want them to make a couple changes there, and eventually everywhere. When new champions get introduced the likelyhood that they even consider the other game modes is slim to none. Sad as it may seem, they are around simply as a way to enjoy the game in a different way without feeling like you have no other options. while originally they may have had ideas of grandeur for these modes, I have a feeling that when the game really took off and the competitive scene took shape that much of these plans were pushed aside as a more important direction came into being. If they were able to put the competitive scene on hold for a year they could have the time and resources to better accommodate the other modes but that is not possible.