The point is that from a development point of view, the tournament is great. It's easy, infinitely repeatable and all they need to change is the rewards. To make a single "very hard" event requires development time and a LOT of playtesting to ensure the right level of difficult (with tournaments, approximately .02% of the population unlocks the character at 7*). And that labor has to repeated every time they want to release a new character in this format (or else people complain that the exact same event is used and it was *way too hard* the first time around as well, and why do the exact same people who farmed some obscure shitty characters like CUP and JKG get the OP new toon?).
So while from a player point of view, tournaments are quite shitty (although I still think some fairly easy tweaks could make them very enjoyable), from a development and content creation point of view, they are excellent. They are here to stay.
