Activision was involved. I'd bet money on it. Bungie had something a little more hardcore in mind and they were scared it wasn't casual enough for the COD crowd.
I'll go along with this.
Bungie was happy to accomodate hardcore players before.
A possibility. but i think a year from now Destiny will be a more fleshed out experience. I look at Diablo III as an example of how a game can change and grow for the better.