It was very hard to imagine how Twitter the company would make enough money to justify the investments it had taken by that point if Twitter the service looked more like Diaspora. You on,y have to look at Diaspora today to see that it's not obviously meeting the mission that Twitter serves today.
One interesting aspect of this is you had people like Alex Payne voting with their code in the form of the API and later with his feet after the company was clearly going down the ad-supported route (and hiring a lot to support that model -- you need to build a large amount of revenue-oriented infrastructure in that world). The API then had to be pulled substantially back because it didn't fit the revenue model, something the developer community still hasn't forgiven Twitter for.
It's amazing to me how much of what looks like corporate BS can be traced to individual personalities and their debates, or the echoes of their debates.
[to be clear, all of what I've outlined can be gleaned from media reports, books and presentations about Twitter over the years. While I am an ex-employee, this history is available to anyone who either was paying attention back then or has a small amount of investigatory skillset.]
Fastmail et al. show that you can run a business on a protocol, even if it won't necessarily make you a unicorn.