I feel like a proper review of Destiny would require a good amount of time spent in the endgame. That said, a lot of what the reviewers are saying is taken from at least a light sampling of the end game. The repetitive nature, the lack of great story, those things matter in today's environment for a NEW IP.
Looking at a game like Legend of Zelda, it's story is about as deep as Destiny's. That might be fine for LoZ, as that is the established expectation based on close to 30 years of history. A game generated in today's environment though is held to a higher narrative standard.
Look at CoD, it is expected to be a short campaign and a multiplayer experience. Reviews are based on these expectations.
Destiny, right or wrong, was expected to change the FPS genre - or at least breathe fresh new life into it - and it failed to do so. Thus, the reviews are a bit more critical of it. I personally have played the game for 30+ hours and enjoy it greatly, but I also find that a large portion of my enjoyment is in wondering what they have coming down the pipe with the expansions, and not just the current quests and goals.
