M6s in PF is the most miserable and unfun high end fight in the game

[Absurdity]

2nd floors (which M6S is) don't usually drop weapons.

They kinda do though.
The 2nd floor drops the Universal Tomestone, the item needed for the tomestone weapon, saving you 6 weeks of normal raids and more weapon damage is always a pretty significant dps increase.

Of course it's not literally required to clear, but the additional damage buffer makes it a lot easier, especially in PF where performance fluctuates wildly.