I have no clue if this has already been explained but the loot scaling was done for these reasons:
-Distribution of wealth. The majority of people who don't farm will now get more loot and wealth simply by playing.
-Discouraging farm bots. 'Nuff said.
-Encourage more PUGs and human teams in general. People have been complaining about lack of people to team up with. Now there's an incentive.
So who cares if solo farming has been nerfed. It has always been the lowest form of gameplay anyway.
T

