As someone who leveled every character to level 85 and gl7 (something i am actually proud of) this is a game mode that will not be great for me. I am not bothered by it as like Arena it is a part of the game I will do as well as I can in but at the end of the day I can put my device down and it doesn't matter if I win or lose. The match ups will never be perfect but will balance out over time when they factor in wins and losses. The PvP focused players will rise to the top and have to face each other, while the collectors like me will fall into our own brackets and continue to have fun.
I am not going to say "if you don't like it quit" because if any of us could do that would we really come here to the forums and complain. What I will say is remember this is a game and personally doesn't pay my bills so enjoy what you like and have a go at the rest. How you play the game is up to you, there is not one best approach so have fun and try not to take it too seriously