Problem: A majority of the players are not happy about the new level being released.
Comparison: COC and CR are both progession based games. You know why COC players never feel bad when a new town hall is released? It is because, after the new town hall is released, the overall time taken to be completely maxed is kept same as before it was released. CR players get frustrated because every new level released, the time required to max out keeps on increasing.
Solution: With the new level, you should increase/decrease the rewards/cost in such a way that it doesn’t just keep on adding the amount of time needed to max out.
thanks for the comment. i agree that discounting gold upgrades could be a good option.