It's obvious that Destiny was planned to be more, but that something happened to it about a year before release.
It's actually quite depressing, considering the game that Destiny could've been (and apparently, was, in 2013).
I'm not trying to move blame from Bungie to Activision or vice-versa. But you'd be stupid to think that this (Destiny, in it's current state) is the game Bungie (including Staten and Jones) have been dreaming about since 2004.
Just my two cents.