So what is the point of Pink Bean?

optional super bosses (like emerald weapon) usualy reward the player however with epic items, hence being harder then the final boss.

Emerald and Ruby are not part of the original game (but possibly intended to be in the original). The bosses that people are thinking of from Final Fantasy are like Omega Weapon. In FF8, it gives you nothing except an Omega Badge, and that does nothing at all.

Although, I dont blame people for expecting a reward for beating an optional boss or having a significant acheivement. Video games have changed significantly from the old days, where people mostly played for the challenge and high scrore or other accomplishments for bragging rights.