I spoke at the Nordic APIs 2017 Platform Summit about why Fitbit started adopting JSON API. Here is a written adaptation of my presentation. It addresses the problems API clients had, organization objections and resolutions, and why it was a better fit than GraphQL.
Thanks for posting this here, I was trolling the responses after Nordic and it was on my backlog but really a worthwhile read! Will be keeping this for integration and citation for my talks!
Thanks for sharing