I didn't read whole thread so someone probably already mentioned this.
Rotations were always part of the game since beginning BUT nowadays PvE style with dedicated supports lets you focus on DPS rotations more and care less about mechanics. Even in the hardest PvE content (Raids and CM fractals) you can ignore lots of mechanics due to dedicated supports. That was not possible in such extend in vanilla.
And ye I hate it too so I don't play DPS. Play supports, they have to react and adapt much more.