Why HP inflation is a valid concern

[Baci]

The AP scaling factor is something that affects the entire level range, it doesn't change based on level. Some scale that works with gear at lvl70 might not work at lvl30 or 50. Changing the scaling factor has a chance to break something elsewhere. Changing VIT and STR on new gear only affects new fights and they can be tuned without affecting prior gear and scaling. Separating VIT from AP also doesn't affect incoming damage or non-tank VIT values when they want to tune tank dps, so it's better for balancing.

You mean like SE changed our AP Scaling back to STR which totally did not screw with low level tanks aggro?
Sorry but SE doesnt plan so far ahead. They just change/tweak some stuff and hope it works