While they went a bit far with the yokai-fates I can see why they include fates into a lot of seasonal events: It gives you a feeling of doing this event with a lot of other people - and it is even logical that you're not doing this alone! (During event quests that you do on your own and that require you to do one specific thing I often feel a bit... weird when there are 40 other people standing around, doing the excat same thing.) It includes the event into the world - when properly done! I remember the first moonfair of 2.0 - it was a fate with bombs making their way to Costa del Sol and you had to stop them. It made a lot of sense that that would be a fate - rather than you going to one spot, spawning your three bombs (while 40 other people are also doing that at the same time...) and be done with it. Its a way that makes those events really have an effect on this world - rather than just having questlines. Granted the mini-games during eastern or the letters from the christmastrees did something similar, but for some kind of events - just like the moonfair now - fates actually fit in kinda well!