Why is it better to have the tandems slid forward when alleydocking?

I got instructions for how to buttonhook a right hand turn on the "Most insulting thing another driver can do" thread.

 

On a two-way street with one lane going each way like in the above picture, i will just turn on my hazard lights if I see a sharp curve ahead of me. If the curve is so sharp that I need to drive into the left Lane to prevent the trailer from going into a ditch or hitting a light pole on the side of the road, I will just stop the truck if there is a vehicle approaching me in the left lane, and once the left Lane is clear, then I will pull into the left Lane and proceed through the curve.

 

If the curve is sharp enough, my tandems could go off the road even with the tandems all the way forward.

 

Not necessarily. And even if it did, the ditch could damage the wheels or axles.

 

Why not just put wings on the truck and fly over the curve then?