This whole quest chain does not fit the term "Legendary". It is just an extended RNG timesink designed to keep people playing for as long as possible.
There is only 1 person in my guild who has the cloak and they have raided normal every single week this expansion. It should be about challenges and not whether Lady Luck favours you on any particular week. It is poor design, but that seems to be the way Blizzard have taken many things this expansion.