People use Twitter to broadcast something without wanting to have a real discussion about the thing they just said. There is no discussion possible on Twitter,

People use Twitter to broadcast something without wanting to have a real discussion about the thing they just said. There is no discussion possible on Twitter, as the "threads" quickly devolve into an unintelligible mess. You say something to the public, then you're done. It's purely a channel for viral marketing (also called "push", that word says it all).