I couldn't care less about whether WordPress is a mobile-first platform or how easy it should be to wrap a WordPress site in an app. Most of that is presentation layer problem, which can and should be handled by individual themes and plugins. WordPress themes are incredibly powerful; they can do that and much more. The only part of the presentation layer that WordPress needs to concern itself with is the admin interface.
The "open web" might no longer be a cash cow worth billions, but a significant number of people still love to tinker with it and resist the trend of app-ifying everything. Most of them don't care whether they are worth billions, they care about being open and tweakable. If you don't, then you're simply not their target user.