Black leather

Why is it that leather armour is still better than plate armour for dps warriors? Why can't Blizzard fix this? Compare the two ICC10 chest armour drops:

Plate

Blade-scored Carapace (drops from Deathbringer)
152 strength
72 crit rating
84 haste

The strength gives 304 attack power, plus 20% (zerker stance) plus 10% (kings) gives 304 x 1.2 x 1.1 = 401 attack power.
The crit rating gives 1.57% crit

Leather

Chestguard of the Frigid Noose (drops from Lady Deathwhisper)
200 attack power
79 armour pen
132 agility
99 haste

The agility is increased by 1.1 by kings, and gives crit (62.5 agi = 1% crit). The agility is therefore 2.32% crit.

God only knows how armour pen affects my dps - I assume it makes it go up. According to Landsoul's spreadsheet, a point of Armour Pen is worth about 0.8 of a point of strength to me. This means that 79 armour pen is worth 63.3 strength.

I'm going to ignore the haste, as it isn't worth much and it kind of balances. On the basis that the armour pen balances out 63.3/152 x 401 attack power = 166 attack power, we are therefore left comparing 235 attack power and 1.57% crit with 200 attack power and 2.3% crit - ie 35 attack power in favour of the plate, and 0.73% crit in favour of the leather. The leather is definitely better.

I am currently wearing the leather chest armour.

It's kind of ironic that there was so much clamour from warriors etc for the introduction of a +strength ashen verdict rep ring, when the +agility ring is better for us anyway. Similarly the +strength Quel'delar which I have is inferior to the +agility version.

I think the problem is that for warriors the conversion of agility into crit is simply too good. We get too much crit per point of agility. I wonder if warriors are balanced around being in plate armour, and therefore by being in leather armour we get "extra" dps. The alternative is that we are balanced around being in leather armour and those warriors who insist on wearing plate are gimping themselves.