You can find lots of public games in adventure mode, but almost no one plays campaign mode anymore except for certain achievements. I don't know if you still need to complete act 5 in order to unlock adventure mode or not, but if you do, I can give you a hand when I get home from work this evening (around 8:30pm est).
also, fyi: the hardcore forums on battlenet:
http://us.battle.net/d3/en/forum/5386230/ is more active.
This post was edited by StubbornMule on Jan 28 2016 12:18pm