HAHAHAHA DW Frost DKs spammed howling blast and Frost Strike during MoP. Ive been a consistent top 100 player when i played seriously..Don't tell me I wasn't playing it right.
I will say my favorite iteration of any dk spec was also during MoP with festerblight...but that was an unintended spec and abused the snapshot mechanics of a trinket. But again you mostly used outbreak(for the high powered diseases), festering strike and death coil to keep high powered diseases rolling...you maybe weaved in some scourge strikes here and there...but for the most part you used festering strike and deathcoil with outbreak anytime you could make your diseases stronger than they already were. So yea...i wouldnt say there was a lot of depth to the rotations when GC was there either...they started getting much simpler in Cataclysm and seemed to have spiraled to what they are now...so some could say he started the simplification of rotations.