Today's Reddit is a mire of ephemeral pop commentary, censorship, and automated flagging. It's like the leadership cares about engagement, not discussion, and they're willing to let people talk into the ether to drive the numbers up. The audience quality bar has substantially dropped in all but the most niche topical subreddits as well.
Twitter and the spinoffs are all too high drama for me to engage in regularly. Everyone is playing morality sports or trying to game for traction.
I miss being able to hold a no-stakes, high quality discussion amongst peers. I feel like we need anonymous P2P social networking. I don't like other parties being the arbiters of information flows, and I also don't like bad agents seeking to tear down those that go against their personal brand of ideology.
Slashdot holds a special place for me though. It just happens to be the first place I commented and joined in discussion with a large group of strangers.