Others read what you post and you read what others post. What is there to get? I can understand not liking the format or similar concerns, but if you don’t get Twitter… did you not get irc also?
If I tell someone something in IRC (or any chatroom or forum) they will almost certainly see it an likely respond. On Twitter, it will likely be completely and utterly ignored if its at anyone with a remotely high follower count. Most people don't enjoy the feeling of being ignored.
Ugh... IRC was one of the most infuriating platforms to use. I was so happy when forums took off enough to replace it. Having to use IRC was one of the worst parts of working at canonical.