> The Flow team doesn't seem nearly as interested in usability/adoption as the TypeScript team
It makes me sad that you think this. The team cares very deeply about usability and adoption. We've committed to making it our sole focus for the current half. I was brought onto the team to focus on the external experience and adoption because of my experience working on Babel.
We're solving a very difficult problem space, and we're doing our best to do it right. Trust me that we're thinking about all the same things you are and finding ways to address them.
Also, I must say that I agree that the TypeScript has a massive lead in the community and ecosystem. It's just our opinion that we've set ourselves up to do even better, we're just now switching modes from making the type checker awesome to making the user experience awesome.
If you have any concerns about the experience we're happy to hear it. Having a rapid constant feedback loop is important.