You gotta take into consideration the damage bonus and haste as well.
Case Study!
http://lucy.allakhazam.com/dmgbonus.html
Exquisite Velium Zweihander: 32/36 = .889
Carved Dragonbone Spear: 25/30 = .833
According to the table linked, the damage bonus for the Zweihander at level 60 is 31, and 29 for the Spear making their damage 63 and 54 respectively. Before the bonus is accounted for, the Zweihanders 32 damage is 28% greater than the spear, but with the bonus figured in it drops that figure to ~16%. This closes the gap on the ratio significantly.
Exquisite Velium Zweihander: 63/36 = 1.75
Carved Dragonbone Spear: 54/30 = 1.8
Now haste. I don't think it's too aggressive to say this guy might have good haste if he's got epics and Swiftblade of Zek, so let's just work with a capped haste for the sake of discussion. The new delay on the Exquisite becomes 18, and 15 for the spear.
Exquisite Velium Zweihander: 63/18 = 3.5
Carved Dragonbone Spear: 54/15 = 3.6
The attack rating difference due to the spear being a piercer is another problem altogether. Maybe the speed doesn't create as many more double attack opportunities as I thought, but the ratio alone isn't everything.
Edit - I was typing this as you guys were responding.