But a columi team(which is most of the players who can beat it) could get some upgrade from the boss.
No, it's to let decent players be able to get upgrade.
You want a player that requires full Columi to get a direct gear upgrading from fighting every boss in the HM LI. I understand that.
But since HM LI has no lockout, it would become an unlimited Rakata farming spot. This is why dropping one piece of Rakata at the very end is fair.