Why can we not xmog 2h swords and axes with polearms?

[LazyViking]

I know in retail you can Xmog 2 hander swords and axes with polearms so when I came to learn I can't do it on this server I just had to come here and ask, why?

I'm a hunter with the bis polearm and just picked up Edge of agony and really want it as my xmog but I'm super bumbed that I can't. WHY?!?!

[skullatbash]

these are the rules:

1H Sword <> 1H Axe <> 1H Mace
2H Sword <> 2H Axe <> 2H Mace

Polearm <> Staff

Bow <> Gun <> Crossbow

Daggers <> Daggers
Fist weapons <> fist weapons
Wands <> Wands
Shields <> Shields

[LazyViking]

But why does it have to be like that?
I can understand with wands and shields, staves only being with polearms, and maybe 1 handers with fist weapons, but why not daggers with fist weapons, polearms with 2h swords, axes and maces?
polearms are treated just the same as 2 handers, so why not allow it? the only way I can see it not working is if a class can't use a specific weapon.