Actually i275 would have been objectively better, and not really all that different. It would please all demographics and would have not caused this storm both in game and on the forums (a storm that I might add gives diadem and the future of the game a bad reputation). It would A) please the raiders who have another means of gearing alt jobs (as the RNG would be less taxing), and B) it would give another means of catchup to casual players (as it is an endgame weapon that isn't as taxing as anima or raid), and it would be a good weapon that doesn't outgear endgame.
Making it i280 does nothing except shift the endgame goalpost, we already had an endgame which was i275, that is still valuable regardless of where you are at in raid. I also had another solution to this, although its implementation is a pipe dream:
What if we had an i275 weapon that had random stats (the point values being equivilent to anima and relic), AND increased spiritbond gain as a passive. One thing that will not become irrelevant in stormblood is materia, and having a weapon that aids with materia gathering is both fitting for diadem, and a form of sideways progression, THAT is very much incentive that does not invalidate the other weapons. This weapon would be gathered by collecting 3 "broken coven pieces" which would be dropped the same way the weapons are currently, and traded to an NPC for a job of your choice.
Edit: to add to the above, make the missions more frequent, and maybe drop more than one broken coven piece.
I could write you a design thesis on why the i280 weapon is badly designed, with charts and graphs and background research into MMO psycology and sociology, would that help show that it isn't just paranoia?
