Methinks "whoops" doesn't fully understand the GDPR.
3 Rectification and erasure
A right to be forgotten was replaced by a more limited right of erasure in the version of the GDPR that was adopted by the European Parliament in March 2014.[17][18] Article 17 provides that the data subject has the right to request erasure of personal data related to them on any one of a number of grounds within 30 days, including noncompliance with Article 6(1) (lawfulness) that includes a case (f) if the legitimate interests of the controller are overridden by the interests or fundamental rights and freedoms of the data subject, which require protection of personal data (see also Google Spain SL, Google Inc. v Agencia Española de Protección de Datos, Mario Costeja González).
There has to be some condition or grounds for misuse of data, from what I can tell. Also, what personal info does POTN really have of any of us other than the info we offer up willingly on posts we make or the limited info when we register.
As to the rest of the discussions, I guess I am not following. Yes there are many that registered that don't participate and just read posts, or have completely walked away from POTN. Sometimes this hobby may feel more like a job, and people quit it, or they get rid of gear, or they have life just happen to them. I can completely see that as a valid reason why one wouldn't frequent POTN any longer.
I used to own a corvette and was active on one of the large corvette forums. I got rid of the car after a few years, I engaged with the forum for a small amount of time after, and haven't been back in years.