whats up with Riot's fetish with reworking champions to become sustain tanks

What? How are shen or poppy sustain tanks. Sure they both are tanky but neither of them have sustain in their kit. Shen has very clear windows of damage reduction through aa dodge, passive shield (which relies on spell casts). Poppy as well has he shield for 3 sec and her w to make her tanky but neither of them get sustain. Maokai is a ok example of a drain tank (in a teamfight with spells flying everywhere he gets some nice sustain with his passive)

Warwick and Yorick were already drain tanks before their reworks but they were just badly designed ones.

[{quoted}](name=General KogMaw,realm=NA,application-id=3ErqAdtq,discussion-id=hyVOFg5A,comment-id=,timestamp=2017-02-24T06:00:35.788+0000)

shen, poppy, yorick, WW

Shen and Poppy aren't sustain tanks, Yorick already was a sustain tank (and his sustain has been seriously lowered compared to what it used to be), and WW has always been a sustain tank.