We can speculate why Jack left, but the lagging stock price certainly didn't help him. So if anything, rather than criticizing him for not giving away the content for free, it seems the guy should have done more of the opposite (to prevent someone else taking his job who will do all that and then some).

Twitter never "paid the bills" under his leadership. That's what added insult to the injury of removing previous open functionality: they pissed everybody off and didn't even make money as a result. A better idea has been obvious for more than a decade.

Twitter is most valuable to the "influencers" who have lots of monetizable followers, e.g. the various Kardashians with their beauty tips. Therefore, those influencers should be charged for the value that Twitter represents to them. They would gladly pay a percentage of the fees they receive for marketing the various products they recommend, for a Twitter experience that made that marketing more effective. It's hard to imagine why Twitter executives have missed this.

Charge the kardashian clan x amount of dollars to run a managed version of Twitter's software on kardashian.com and allow for full interoperability with other services that speak a common protocol (the w3c has a protocol. use it!)

you can also have governments and other institutional actors running the hosted software (then you can have @[email protected] and @[email protected] and @[email protected] and @[email protected] and @[email protected]) these all can operate as white-labeled instances of the managed Twitter service (basically, how Google Apps worked but with Twitter's software).

Everyone knows that audiences can go anywhere (every time there's been a huge technological shift they've made the jump - Radio -> Television. Newspapers -> Twitter et cetera). Influencers go where the engagement is. What I'm trying to say is pay attention to where the audience is at.