I think everyone has understood / noticed that most of the costumes / mounts are in Crown Store.
Store updates are released almost constantly 2 times a month and that's about ~14 mounts. Why not take at least ONE of them and add it to the game every update for any achievements, story, mini-games, craft, etc. Imagine how much completionism content and mounts we would have all this time.
I remember how I did Dwarwen Ebon Wolf a year ago and this does not compare with the emotions of receiving it, unlike if I simply paid for it in the store