I think for events like the current one, there's no need for a ladder. After 2 weeks (or 1 week) of constantly farming, I'm sure players do not want to farm more to compete on the ladder.
Therefore, why not just move the ladder reward into bazaar and remove the ladder? For the current event, the ladder reward is pixie so the dev can put Limited: 1 pixie selector in the bazaar for 50k point (or whatever the dev deem is a fair number). This way, everyone can get the reward and it's not just cater to whale who can buy a lot of energy. It also makes the game less grindy for everyone and players can go at their own pace instead of competing with others.
I'm sure even if this event were to last for 3 weeks, without a ladder, players can choose to invest their energy into elsewhere for the last week and people would complain less.
Credit to Yukie for suggesting this to me.