Placements for rank are making players quit League.
Riot, I don't understand the value you are trying to create by placing Plat players in Silver and Diamond players in Gold and so on.
Who wants to grind ALL SEASON to achieve the highest rank you can, such as Plat levels, go 7/3 in placements and get placed in Silver?
If they belonged in such a low division, then wouldn't they fall to that division naturally?
The current system just seems pretty shitty. I've read a lot about high level (plat and up) players that feel encouraged to quit because that sounds better than grinding through lower divisions again.