This point needs to be made more. Those who want IDs preserved when a user leaves the site need to understand that, legally, iNaturalist doesn’t have many options. The “right to be forgotten” provision in GDPR is taken very seriously in Europe. (No great surprise, some of those countries had secret police in living memory.) I doubt California is quite as zealous enforcing CCPA, but it doesn’t have to be. If iNaturalist wants to save IDs from deleted accounts it would have to anonymize them to the point where there is not only no chance of the original user’s identity being recovered, but also no chance of being sued by an irate ex-user. The only realistic choice would be a single “AnonymousUser” which would quickly have more IDs, and a greater variety of IDs, than anyone else. Since the quality of AnonymousUser’s IDs would be impossible to verify (since it’s an aggregate of any number of people of any range of abilities) they would be completely worthless. Cleaning up that can of worms is a job no one wants.
How often does account deletion occur? More importantly, how often does the deletion of a significant account (large number of obs or IDs or hard to replace specialist) occur? To read some of these forums you’d think it’s a weekly occurrence, but I find that a little hard to believe. Hard data would be useful here.
Somebody has to ask the next question; it might as well be me. Even if a user deletes their account, removing thousands of obs and/or IDs, so what? INaturalist is not (and this is by conscious choice) a scientific database. If it were, expecting a certain level of permanence to the data would be reasonable. (It might even be allowed under GDPR.) But it’s not, so it isn’t. As long as iNaturalist remains a social media site first it has to accept that data comes and goes.