Why gut the AP junglers?

Champion.gg has finally updated with Plat+ stats for every champion, and a clear pattern emerges when you look at the jungle winrates:

Diana: 52.96% > 47.02% Ekko: 48.89% > 47.80% Elise: 50.96% > 48.48% Evelynn: 51.61% > 48.37% Fiddlesticks: 51.08% > 50.58% Fizz: 50.83% > 45.52% Nidalee: 51.63% > 44.0%

Not a single AP jungler hasn't seen a drop in win rate this patch, primarily thanks to the unwarranted Runeglaive nerf. While some of the changes aren't that extreme, the drops for Diana, Evelynn, Fizz and Nidalee are extremely harsh. Why? Were any AP junglers actually overbearing? Elise and Diana at a push, but aside from that...

I really hope something will be done for AP junglers.