I don't know that I can completely agree but I know what you are saying. And there are multiple things now rolled into this thread. It is true that something was off with the distribution of the Christmas collectibles (way too many candy canes) but if you got at least 2 drops each day you would have gotten enough of each to complete the achievements.
As far as getting "everything" that depends on what level you are, how many explorers you have, what means you have to trade with, etc. So some players would have needed to prioritize what they wanted first.
However generally I would say yes. By being active and doing the given quests, opening doors and so forth (plus some nice extras offered for nothing from the game itself) I would find it hard to believe that anyone that put in any effort at all would not be able to get at least a couple top goodies. I found the event very generous in general.