@Angus

I think your list is a little misleading. I play a rogue, and I looked over those weapons, and those are not all rogue weapons.

32 weapons are in your list.

2 are white items.
3 are maces. Because of the lack of off-hand maces, it is very difficult to be a mace rogue right now.
5 of the nine ranged weapons are poorly itemized for rogues. (One is a tanking gun, for instance).
2 of the remaining weapons are not rogue weapons (as they lack agility).

That leaves 20 weapons a rogue could want to equip.

Now, a rogue has two different PvE trees to choose from. Assassination needs daggers in both hands. So the 2 main hand daggers (certainly) and the 2 off-hand daggers (to a lesser extent) are for that spec.

Of the remaining 16 weapons, 8 are slow weapons (i.e. rogue main-handers) that would appeal to many DPS classes. The remaining 8 would be the fast 1.5 speed weapons you are complaining about. (Although I believe frost DKs can use fast weapons in both hands if they choose).

Combat rogues are different from enhancement shamans (and other physical dps classes) in that their weapons need to have different speeds. Hence, we cannot pull from the same upgrade pool for both hands. If you get a better mainhand weapon, you can switch your old mainhand to your offhand without penalty. As a rogue, I have to upgrade each hand separately. This is why rogues have about twice as many weapons in the patch. You can wait for the slow axe to drop again. I have to find a completely different weapon.

It doesn't seem like any great injustice has been done here. It merely seems that the different mechanics of the classes force one to use more different weapons than the other.