Even in ARR, not all boss FATEs can be one shot. Some can, yes. And most FATEs aren't boss FATEs to begin with. So you're dealing with a minority of blue mages who might do that, in the chance that it was a boss FATE that can be one shot, out of all the FATEs in all the zones in the ARR regions, and calling all blue mages griefers because of it.
Each medal can be earned in multiple zones, each zone has multiple FATEs, the FATEs respawn at a decently quick rate. Just stop the hyperbole. This entire thread is filled with hyperbolic statements or outright lies.