I am probably going to pass 30,000 tweets with the message that this post will trigger.
When I started using the Internet, NetNews was the way people publicly communicated. Used to be UUCP, thankfully replaced by NNTP, the newsgroups are almost dead now thanks to the proliferation of the web. You used to be able to read my posts form '92 on Google, harking back to when I was a Clarinet major (and Unix sysadmin) at OSU, but I was posting even before then, back in '89. Probably those are around somewhere.
In the mid nineties, I made use of IRC a lot for public conversation. Thankfully, there are no (public) logs of these conversations.
When TB-L first envisioned HTTP, he saw it as a collaborative medium at the outset, but it took nearly twenty years before we truly achieved collaborative web. Twitter is a public conversation, a collaborative web, and I enjoy being part of it. Are there problems? Sure. Does it sometimes fall short of human decency? You bet. Mostly, however, it is a nice chat amongst friends, with the occasional injection of local, national, or international tidbits of interest, and I can't complain about that at all.