It has more to do with nobody in the dev team, or the testing group, playing SMN. I'm sure people just job swap to SMN for the tests and says "Yea, I could summon this avatar and trigger BP, job works!".
Because the skill over cap system would never have passed if they had any serious testers that noticed that "hey, if I level up a level, my skill becomes uncapped and I lose efficiency" or "Hey, I got 50 skill over cap, which is amazing, and yet it only extends crimson howl to slightly past 1 min duration. What gives?"
I'm just glad they said "Screw this, we aren't adding SMN to FF14", so that they indirectly could admit that they haven't done a single thing correct with SMN since 2001. 10 years and still no clue how you'd make a mage function with a staff, spirits and avatars.