It's not only for Range attack but for mages too. If i'm not wrong is a countermesure against "terrain profit glitches" which appeared on FFXI for kill certain NMs.
For those who didn't play it, it was basically something like: put your mages on a high elevation while the tank on a cliff or lower elevation. If the NM's would perform and AoE even huging the wall, It would never hit the mages. So mages would never have the risk to die about it and the mechanic-strategy of the special attacks of the said NM was worthless.
An easy example: Dark Ixion.