There's already huge list of learnable abilities in Pyros and current BLU will be just as useless for overall gameplay.
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Spells are limited anyway (you can choose only 24) and they could've made core abilities learnable by job quests and others by current system, while also having something like tier system based on strength of spell, where the most powerful spells would cost you entire MP bar and have really long CD, for example. That beats stupid solo mob grind with finite progression and absolutely nothing afterwards (not having DF and allowing unsynch for old content makes chances of level 50 capped character to get into any group very slim).