debate and socializing are mostly nonoverlapping use cases.
Debate should be centralized and public, while most socializing is way better if it's personalized/cliquey and candid.
I think an ideal platform would be heavily inspired by twitter.. one needs to be able to choose who one associates with, but the bounds of one's clique need to organic, people need to be able to come and go effortlessly for group conversations to flourish properly.