Blizzard wanted a step away from memph/pindle running which ruled the older versions (specially with all bots on BNet). They wanted more parts of the game to be interesting for people to hunt items.
So adding the lvl 85 areas was (and still is in my opinion) a nice idea, specially because there are some choices which can be made in 1.10.
Randall
So adding the lvl 85 areas was (and still is in my opinion) a nice idea, specially because there are some choices which can be made in 1.10.
Randall