The gun play was amazing, there was a seemingly endless number of things to do. When I completed things and got better gear I actually felt more powerful. Most of the exotics gave very unique play experiences that were literally game changing (Twilight Garrison was almost like adding another class to have fun with in crucible). The uniqueness of the exotics meant I could do the same activities and play crucible with many different play styles and made it feel different. I had FUN in the crucible. I even enjoyed grinding for materials in vanilla D1, although I know enough people didn't like that so it won't come back. I mean, every Tuesday for three years except for the down time between DLCs were spent raiding with my friends, and there were always 20+ people on my friends list on ready to raid. Literally none of this is available in D2.