I don't mind having to pick through teams that are obviously way too powerful to even try going up against, I don't mind getting a bunch of teams tha
t are pushovers, and I don't even mind an unpleasant surprise now and then. It's just WAY TOO FRUSTRATING to find time after time that a team is WAY more powerful than its power rating AND team composition, levels, and ascension levels would indicate! Their formula for matching simply puts WAY TOO MUCH emphasis on things which have little or nothing to do with how well the team will do in a match!
I can hardly bear to do another match after one after another team that looked on several counts like it should be fairly easy to beat TOTALLY STOMPED my team! And then I get a quest requiring I beat a team with a HIGHER power? Oh, okay, there's one with a higher power and all 6-stars but, HA HA, the leader is only up to lvl 44 and the aura (it was Guardian) doesn't even apply to the arena, and the Doompriest is only lvl 50, no rezzer, and none of them are legendaries. That power rating must be overblown, I bet I can beat them with my all 60 team with 2 legendaries and the epic Cardinal to heal some and rez .... NOPE.
There's only 2 reasons I play this game 1) easy to play--set things on auto and do something else 2) Lots of rewards, or rather, fairly easy access to rewards at fairly regular intervals.
Having an arena that's frustrating and having access to rewards dependent on the frustrating arena pretty much kill both of those.