There has not been an exp nerf and there are players that are receiving the same amount of exp today than a year ago... some even higher.
Before the merge there was a server with a permanent boost to exp, so players from Kaiser server might indeed find a decrease in exp because they had a boost for months.
But besides from that, there are many variables included in the exp formula and some of them might be affecting your result. For example, there is a team attack component and teams today are indeed getting less team attack than before (specially on a loss), but that is something people playing should manage to increase.
