I don't have any inside knowledge, but as a developer using Swift (that followed the Swift web frameworks closely): I think Kitura only existed as a long shot

I don't have any inside knowledge, but as a developer using Swift (that followed the Swift web frameworks closely): I think Kitura only existed as a long shot for kicking off their cloud offering. They were hoping iOS developers would code their backends in Swift/Kitura and host on IBMs cloud. But that never happened - so Kitura was killed. Swift on the server is still niche. And the companies that used a Swift backend overwhelmingly went with https://vapor.codes https://vapor.codes instead. It is faster, and has a nicer API.