Would anyone play this event if there were no rewards?
I think that goes for most events for most people. We're in it for the rewards.
The only one I might personally want to play some "just for fun" is wildlife. But probably not nearly so much as I play it during the event. And the original, harder version with all 5 colors on every board was more entertaining.
St Pat's on the other hand is a bad copy of a genre of game I don't even much like the good versions of. The only fun is in doing the math to come up with your strategy. The actual playing of the event is miserable - repetitive, trivial, and time demanding.
And coming up next we have gem-merging again. Which I find pretty repetitive and trivial as well. At least you don't have to check in multiple times a day for it though.