I'll admit I like this version of Diablo. Looks great, plays well, plenty of potential. I wouldnt play it otherwise But the game is forcing us to farm 1/4th of the world for the best chance of success.
"Lets do a Zoltan run"
"LFG, DH for S.King runs"
"Anyone wanna farm Belial for awhile?"
We don't see this is chat because we have no good reason to expand. Areas should have a bonus to drop certain items. Bosses and sub-bosses should have specific loot tables for attempting to farm specific/unique drops. Hell you can even implement hotzones, a daily MF bonus (past cap) to an Act that rotates daily.
"Hmm, what the bonus act today, Act IV? I'll go farm Diablo then"
A lot of "missing potential" at your disposal. :)