Cashers contribute to the game. They keep it running. Thus cashers should have some sort of advantage. A reward, or incentive to continue the behavior.

Given that Evony has never really provided any incentive before, I will not begrudge the cashers this one, particularly when they have to spend hundreds of dollars to get it.

People getting a huge advantage, skipping months of game play, and having far greater troop production because they got a really nice random drop is however another story.

At least for a forced PvP environment.

Cashers getting advantages is part of playing a free to play PvP game. You put up with it or you buy a subscription to something else.

Random people getting huge advantages that include skipping months of tedious effort is another story. Thats called really bad game balance.