Why does SAoGK not scale to player level?

Why does the Secret Armory of General Knox not scale to player level during PT 2.5?

After playing through DLC1 - The Zombie Island of Dr. Ned and DLC2 - Mad Moxxi’s Underdome Riot, I am angry and disappointed to find that DLC3 does not scale, and that I will be fighting enemies far below my own level, probably for the entirety of the DLC.

I expected that this would have been addressed for the Enhanced version of the game—it had always been one of the most glaring issues to date.

So why?