its not
they made it so you can get more exp then you should
they programmed it the way it is
they didnt expect it to be so high, but it is
its not like they misprogrammed anything, or there is a loophole to abuse
it is the intended mechanic, which they failed to adjust properly, that is why you can not define it as an exploit
not lets say people found a way for the chain to not ever drop, and they used that to mass 1000 chain mobs and always keep a bonus.... THAT would be an exploit
