Good thing you thought to ask here before repeating it. (Rarely the case with reddit! +50 dkp!)

In actuality, the Lore Book II specifically states:

It is interesting to note that, despite distinct Elezen origins, the rapier never became popular in the city-state of Ishgard. This is believed to be a result of the nation's long history of strife with dragonkind—weapons with far more reach, such as the lance, being valued over those better suited for close combat. It was instead the Elezen of Amdapor and Mhach who fled to Gyr Abania following the Fifth Astral Era's great flood who introduced the dueling weapons to the region's red mages and oversaw the eventual addition of the trademark aetherial mediums to their hilts.