I think it's different for everyone, however Destiny was made with PvE as the focus. While you're right in killing AI isn't as dynamic as another human player, it's the co-op aspect that I personally get elation from. I played this game with my IRL friends and it was such a great experience. Coming off the back of playing Gears of War with them it was already something we were used to, though FPS isn't our style of choice, the variety of classes made it easy for us to get over that. The first time we successfully raided (I say successfully because the actual first time we tried to open the vault as a fireteam of 3 at level 25 we got squashed) was an amazing experience. It was true happiness when we actually completed it something like 14 hours later and then there was hard mode, urgh so good. We love a challenge always have so anything difficult in co-op is right up our alley. Gonna be honest I never even tried crucible for the longest time because as I said, I'm not a big FPSer and I'm not in the slightest competetive. Add to that that I hated Halo PvP and I just steered clear. Of course since then this has changed, but PvP doesn't give me anything like the co-op experience does, probably because in co-op PvP it's hard to get people to work together. It's like CoD where everyone just does they're own thing. I'm just not into it. Anyway to each their own, but the devs need to understand they sold this as a PvE experience, I don't think many want to "Become Legend" in the Crucible.