This approach also completely overlooks the fact that most sophisticated products are multi-client: web and native mobile app. In this world you want APIs that

This approach also completely overlooks the fact that most sophisticated products are multi-client: web and native mobile app. In this world you want APIs that can mostly be shared across platforms, as mobile should operate as more of a thick client anyway given network latency. So supporting HTML over websocket as another client is pretty incongruous from an architectural perspective.