This is mostly a localization topic rather than a UI topic, but here are some points from the several times we've discussed this topic in the past.
In most of Final Fantasy history, spell names have used suffixes xor spell names have used numbers, with a bigger suffix or a bigger number designating a stronger spell. This works largely because in most of FF history, AoE spells have simply been single target spells dispersed over all targets. The notable exception is XI, which because of its MMO-sized spell set, needed ways to differentiate between spells with different effects and so introduced suffixes as targeting indicators (the naming system actually became an interface feature) used concurrently with numbers to designate relative strength.
While it sounds like a simple thing just to rename all the spells using some sort of suffix system, it's not so straightforward.
Consider BLM and WHM which are pretty much the only jobs that would be affected by this.
If we just changed the numbers to suffixes, we'd get this:
Code:
Spell I II III IV
Fire Fire Fira Firaga Firaja
Blizzard Blizzard Blizzara Blizzaga Blizzaja
Thunder Thunder Thundara Thundaga Thundaja
Cure Cure Cur?? Cur?? --
Medica Cur?? Cur?? -- --
Stone Stone Stonra Stonga Stonja
Aero Aero Aera/ora Aeroga --
Besides the obvious question of how to allocate the Cur- names between Cure and Medica, we have a naming scheme where the suffixes don't really have any meaning other than to sound cool. Since the suffix system doesn't have any mechanical purpose over the number system, the consideration comes down to, "Will a typical player be able to make the correct association between a spell and its effect?" While it may be easy for some, and certainly comfortable for a Final Fantasy fan, some players are playing XIV as their first Final Fantasy. The number system means those players don't have to accustom themselves to set of suffixes that don't encode any information. Is Fira the AoE spell or is Firaga? What about Aerora or Aeroga? Stonra or Stonga?
If we map the spells to a suffix system based on effect, we get something like this:
Code:
Spell I II III IV
Fire Fire Firaga Fire II Fire III
Blizzard Blizzard Blizzara Blizzard II Blizzard III
Thunder Thunder Thundaga Thunder II Thundaga II
Cure Cure Cure II Curaga --
Medica Cura Cura II -- --
Stone Stone Stone II Stone III Stone IV
Aero Aero Aero II Aeroga --
(I've struck out the spell names that wouldn't change.)
This could have worked well had we used this system from the beginning. It's too late for that now, though. Changing the system would cause all sorts of trouble. Of the spells that would be renamed, almost half of them would be names that we've already been using for other spells for the last four years. Discussions of rotations and tactics between veterans, newbies, and returners would be prone to misunderstanding. And anyone who looks up one of the many out-of-date guides online would just end up even more lost.
In short, the ship has sailed. We have what we have.