Why change Dorans Shield from a good Tank item vs Ranged, to the opposite?
Before it took some damage off each auto and ability and gave some hp/5 to be able to cautiously farm a bit.
Now it does the opposite. It gives a one time, slow ticking regen off damage. Which actually rewards (rapid) auto attacks and high mobility dualers. The tank only gets that full 20hp per hit if they back off after every such hit for a long period of time. Good luck cs'ing.
Which brings me to Ranged Toplaners and Rivens and such taking it now. Because it nigh completely negates any trading Tanks not called Sej do now. It even helps with last hitting.
Personally I wouldn't be surprised if soon you find Adc starting the item.
I'm sure it can be put more eloquently, but I believe the point stands.

