This is true for some holidays, Brewfest can be done in a day as with Winterveil. Only a few holidays have multi-day's worth of things to do that aren't due to a 24 hour lock out. The year up to Legion was the most active I'd seen these events since Vanilla and yeah... they died again because we pretty much did everything. I prefer the model of each year they change it up with new stories and rewards. I will admit I am glad I don't need to farm/grind current content to just to try and get a Santa hat. (which wouldn't be so bad if WoW was even a half way decent game anymore)