GMS Server Status Discussion 2012-01

That logic seems backwards - The higher the latency the more visible it should be the further away you are, not the closer.

That depends on whether the difference is fixed or relative.
If they changed hardware or otherwise caused a fixed additional 0.02 sec to everyone's ping, then it would be much more noticeable to those who were at 0.07 (and changed to 0.09) then to those who were already at 0.15 (and changed to 0.17).

It's true that if they added 30% to everyone's latency, those who were already slow would suffer much worse, but I doubt Nexon's changing their equipment or routing could have that wide an effect.