Cambridge Analytica downloaded data? The API worked as expected and people should have been smarter to not share data.
Facebook has special APIs for phone manufacturers? The API works as expected and people shouldn't buy phones from the manufacturers they don't trust.
But, here's the thing - FB shouldn't have allowed this at all. In one part, security is about making things harder for people to break-in. Currently, manufacturers can use official API to siphon off data to non-FB servers. Sure, manufacturers could run some kind of MITM attack to achieve something similar. But having an official API is a strict no.