I bet most complaints would be gone, if they simply not named these Items “Legendary”.
Like “Superior Rares” or “Hello i am an Upgrade material most of the time” and changed their colors to brighter/darker Yellow.
Humans are Creatures of Habit, so if they see Legendary with the red colors in d4 it automaticly get associated with must be a “decent upgrade” . But that is Blizzards Fault, for imprinting those colors in our brains.
We dont know how rare the “real important(Uniques+)” Items are.
Its all speculation, until we know all the facts, how all rarities work @Endgame.
Might be that Beta had vastly improved drop rates.
Might also be that uniques and higher tiers are so much stronger then yellows/legs that in reality they are only stepping stones, and really needed to drop like crazy to progress.
Or they really messed up, who knows.
Only time will tell.