Just Figured Out why supports aren't warding anymore...
Wards placed: 4 Grade received: S
Players are catching on to the grading formula. Wards apparently aren't needed to get an S. And players with high KDAs AFK farming to get their farm up even if the game becomes lost as a result because farm counts towards S grade? Yup. Because even if you are crushing the game, one unlucky death can knock you out of S grade.
Of course, these are exactly the reasons why RIOT didn't release the formula for success.... but eventually players start to catch on anyways. And if you think this isn't really the way to get an S, well, there are plenty of players who apparently disagree.