So why is Tetragrammaton have that perticular name?

[MilesSaintboroguh]

I believe they said in the past they did not use the -ra, -ga, -ja convention as new players got confused and did not realise which was the "better" spell.

Ironically, I think FFXIV would benefit from using this wording, as it would force new players to read the spells and realise there is not really a better/worse version of each spell, but that they are different and to be used in different situations.

The fact they don't is the reason we end up with Fire III spammers occasionally

If people never read instructions given out by the NPCs in the Steps of Faith trial, what makes you think a name change is going to have them read it?