Here's the basic argument against:

Scrolls cost money.
Gear cost money.
Mages have to buy gear and scrolls more so than any other classes and are therefore slightly gimped while leveling due to gil constraints. Gil doesn't flow as easy as it once did and therefore it would be harder to have to go back to town and buy spells every two levels and especially so if you don't have the gil, leading to the casual crowd they desperately want to capture being utterly gimped.

-side argument a: action cost system, why pay for spells that you may never get to even use or which sit at the bottom of your hot bar. This about this you bought all the elemental nuke scrolls but you really only use 1 or 2, that would blow (just an example not saying this is true)

-side argument b: people could take advantage of scroll drops. Monopolize drop and set price high, done and done. Even worse scrolls could be based on your nations standing if they add it like xi, leading some people to never obtain certain scrolls because their nation has been sucking it up hard lately.

Therefore no scrolls.

I'm not casual but seriously eff buying scrolls, I would like epic abilities eventually that maybe use guildmarks or some sort of currency, but not too many, there does need to be a base amount of spells everyone should have just to make the action cost system work.