Azir ultimate is pretty much a perfect example of powercreep.
It's an aoe knockback that does damage creates a wall for 5/6/7 seconds which CANNOT be dashed through and your allies can actually move through it and they get an ms boost when doing so. And to top it all off its tied to a champion that has an extremely long range dash and who can create towers to wall you into on YOUR side of the map.
My point is the nerfs are absolutely justified.
People on these forums complain about overloaded kits all day long and then when azir is on the table for nerfs they complain? Are you joking?