I blame Juan Diaz.
Yes: Slaanesh is too mature.
Yes: Slaanesh was sleazy in a bad way.
Yes: Slaanesh's models were bad.
Yes: As long as it's replaced.
Yes: Slaanesh was just too 80's to live.
No: Slaanesh was cool!
No: Slaanesh represents a mature aspect of the game I value.
No: Slaanesh may be dumb, but it's pat of the game's heritage.
No: Slaanesh is too critical to the fluff
No: I hate retcons on principle