The problem, in my opinion is the same 3 people keep winning over and over again.
Fact is those 3 are skilled players. Fact is those 3 people put a wall before the skin (which they already have) for other players. And this is a problem.
Another fact is a lot of not-so-skilled players participate in the event only for the skin, because if you remove them, probably there will not be enough people to even start a match. This situation is leading those players to quit the event (fact is the first week in Jericho there were 400 players online and tonight there were 176 - 3 weeks later). If the reward were obtainable, ppl would return to play again, but instead, they keep getting frustrated and quitting the event.