We got a lot of good feedback, and we're going to go back and figure out how to make group chat even better. We've learned a lot and discovered a lot of issues -- and we think we have good ideas on how to improve them while keeping the spontaneous nature of public chat alive. It's too much fun not to!
But if you need your HeyTell group chat fix, there's hope on the horizon. In the next month or so we're going to allow users (iOS & Android!) who have the Groups extra to create Shared Groups, which allow group members to "Reply All." Stay tuned!