I want to support this (especially Ascian robes) but!...

Not yet. There might be a time in the timeline of the game, maybe an Ascian-themed expansion where it would be lore-wise to let it be available and only in the mog station.

It is unclear if we will finally visit Garlemald in the next expansion, maybe we can get the garlean race as well, but in any event, Ascian robes and Garlean armor (such as Regula Van Hydrus or Gaius Van Baelsar) should be available only at the proper time, and that time is definitely not yet. Either the Ascians (only Elidibus is making a presence now, as Lahabrea, Igeyorhm and Nabriales are out for the moment) should evolve into a different robes or appeareance, then make the old robes available, or wait until the Ascian saga is done with, then make it available. But having tons of people running around in Ascian robes would be a bit of a lore-breaking feature for now.

Again I support this, but now is not the right moment to do it. Later yes.