can anyone tell me exactly what the problem is with short 'spammy' regular mob encounters? can anyone give me empirical evidence suggesting short spammy fights leads to a base of bad players?

the only way to make sure players suck a little less on 'boss' content like ifrit/moogle is for them to have *more practice* on 'boss'-type content, and learning what works best and what rotations to use and blah blah... because 'boss'-type content isn't the same as leveling content. if it is, either your leveling is way too hard or your bosses are way too easy.

(and actually, 'bosses' in this game ARE way too easy, but that's another topic)