Facebook’s response seems perfectly reasonable to me. - Obviously in order to integrate FB functionality into a Mobile OS UI requires an API to render the data being displayed. - If your phone has a home screen widget which shows friend data, obviously that friend data came from a Facebook API call. - If you type your Facebook username and password into a settings dialog in order to enable that home screen widget to…
Because that's where the ground of your argument sits: because of server-side "rendering" the data must be sent to the servers of the software author, in this case Huawei but doubtless many others, instead of to the device that actually displays the information.
... and that's exactly why everybody's doing cloud based software. Because it allows them to abuse this. And once they've got the customer by the ... they ask money for that.
Cloud based software is how the author of a todo-list app can hold users' data hostage more effectively, more detrimetentally to the customer than Microsoft's monopoly that was blown up in the cause of justice.