Rabble was the first Eng hire at Odeo, the podcasting startup founded by Noah Glass and Evan Williams. When Odeo didn't gain enough traction and they were figuring out what to do next, a small Odeo team (which included Jack) prototyped Twttr. And the rest is history.
Yeah, huge amounts of work from prototype to world changing platform happened after i left. Nobody created twitter, rather it was the collective work of many.
Twitter started out as Odeo, we started with Ev's investment in Noah Glass's idea for a podcasting platform in 2004. After a few months in early 2005 Ev joined full time. Biz and Jack joined in the fall of 2005 almost a year in to the company. Twitter itself was created as a prototype in Feb 2006, and the current version was launched as a side project in March 2006.
Companies name co-founders based on what's useful going forward and of the dozen or so folks who were at Odeo when twitter was created it made most sense to name Ev, Jack, and Biz as cofounders. Goldman probably turned down the offer to be named as a cofounder, and the rest of us weren't given an option. Later Hatching Twitter came out and Noah was added to the list of founders.
Starting companies is hard, running them is hard, the drama of who said and did what is interesting but it doesn't teach us much about why the platform ended up like it did or provide insights in to creating new companies.