The most recent ones have been an awful lot of work for so little “rewards”. Half a hero isn’t even worth my time because there’s no way I’ll be able to get the other half. Trixie and ghoul? Who still needs those heroes?
The powers that be (IGG) are the ones who ultimately decide on the event rewards.
I agree with the OP though. I've been trying to get people to do these events, and often get told the rewards aren't worth the time, even being free!