I think Ben Kuchera over at Polygon said it best.
I really like playing Destiny, despite it almost aggressively trying to be unlikable in the story department. For reasons I can't comprehend, everything important in the game is named with the exact same naming convention of "the Noun." I guess it's supposed to sound weighty and serious, but it mostly comes off sounding like Halo fan fiction, written by a 14 year old with an extremely limited vocabulary. Also, Peter Dinklage sounds like he'd rather have been anywhere else while recording lines for this game.
And yet I want to cut this post short so I can get back to playing it. Because it's fun. Personally I'll take shooting aliens with laser guns over shooting virtual people with recreations of real life weaponry any day (that whole mixture of glorification of American gun culture and ooh-rah military bravado that Call of Duty and Battlefield traffic in really rubs me the wrong way, but that's a blog for another day).
I don't think the reviews are too harsh. I'd give this game a 7 out of 10, but that's fine. A great story would have been fantastic, but just the sheer fun of shootin-n-lootin is doing it for me right now. I'm excited to see what the game becomes as both Bungie and Activision seem quite committed to it lasting a long time (and raking in a boatload of cash). Go play it!