It is not FUD. I work at a major telco/ISP, specifically on ensuring GDPR compliance for a number of applications.
Personal information that is deliberately and freely made public by the owner of that data (ie. you, the user) is free to use, both for the service on which you make it public, and for anyone who happens to read it on your publicly visible profile/wall.
The reasoning is that you made a deliberate choice to make this information public, meaning you have given consent to public viewing of said data.
What this Facebook issue is about, is the collection of personal data that you have not made publicly accessible, because it is private to you. FB is using this data to tailor ads and to modify your feed, giving you politics you agree with, suggesting pages for you to join, and so on. FB is also profiling you and inferring your private information, and using that to track you across the web (on every single web page with an FB "like" button, for instance). They have a disturbingly detailed profile on all of their users, including highly sensitive data such as political standing, sexual preferences, medical history, even possible infidelity.
FB is perfectly usable without giving them access to any other personal information than a fake date of birth and a throwaway email account. It is perfectly usable with "targeted ads" turned off. It is perfectly usable without the "optimized news feed", it can just default back to a chronological feed instead.
The violation of their users' privacy is not essential to the service FB provides to their users.