Even then, Lit, Ice and Fir, Bio, Pig etc. were limitations of the NES in which all spells had to be 4 digits or less when you got to Lit2, Ice2 etc. As technology progressed, the names got longer.
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If you want to get technical we should all be casting Lit, Ice, Fir etc. The spells have evolved over time so you can't really say the current names aren't Final Fantasy as they really are [aside from Medica], just maybe not from the game you want.