Okay, lets try this a different way...
A creature wielding a double weapon in one hand can’t use it as a double weapon-only one end of the weapon can be used in any given round.
This is the quote you say is relevant. But lets look at it more closely.
It is a conditional statement. *IF* you are weilding one-handed, *THEN* it can't be used as a double weapon.
So the key is to see who meets the first part of that conditional.
ie.
A creature flying can be targetted by magic missle. Is also a conditional statement. But it does NOT mean that all creatures can fly.
A creature wielding a double weapon in one hand
This raises the question of *who* meets this conditional. *WHO* can weild a double weapon in one hand? Everybody? If you say weapon and weilder size doesn't matter, than we are back to the grig using the Huge double axe; and that is patently absurd. So we need to look at the rest of the rules to see who meets this conditional criteria.
Well there it is. A creature one size category larger can weild it one handed. That is the way to meet the conditional. Just like picking a hawk would meet the flying conditional.
Yes, you are right, *anyone* weilding it one-handed is affected by the above rule. But *only* those large enough can wield it one handed. An orc using his double axe is not large enough to wield it one handed, and he cannot fly; therefore neither rule affects him.
Hope that clears things up. I would love to go toe to toe with HS; it is kinda fun. But in this case he is right. (okay, most cases...unless he is being too literal

)
The rule is not useless, but it only applys to certain creatures in certain situations.
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