It sounds like there is a mix-up between the licensing of the “sui generis” database rights and the individual record licenses. There is no need for iNaturalist to be conservative in the licensing of the database, as it only applies to the dataset as an entity in itself, being a collection which may under some jurisdictions have some protection. A CC0 waiver would be fine on the database level, it would not override whatever the license is of the individual records. I feel anything other than CC0, but especially BY-NC, sends a signal that is in conflict with what iNat stands for, as a community of people freely sharing their knowledge with others.
I think it is little meaningful to say that the license of the record is not changed here, considering that the screenshot says “Altered” right next to the “Record license”. I also realize that many users may ignore the licenses, but legally they are in the wrong when doing so. And who knows, there may be people out there who end up excluding the data at a later stage due to the license, which would really be a shame. There is simply no way to track that.
I agree that the observational data is not copyrightable to begin with. That is all the more reason not to put a restriction on it! (Full disclosure: I was one of the contributors/writers on the GBIF licensing policy. It was agreed that copyright does not apply, but CC BY and CC BY-NC were kept in as a compromise, being legally meaningless but in line with scientific practice of crediting).
It seems that whatever license is put on the record level is overridden by the dataset license on GBIF (I have not found any datasets containing records licensed under something other than the dataset license.) That’s not right, if we are going to use licenses the openness can and should be allowed to differ (in both directions).
When this is solved, I for one hope that iNaturalist will waiver any database rights (pretty meaningless in a citizen science community context anyway) through using CC0. Users can still put whatever license they want on their records, and data users should respect it for what it is.
Ping @dagendresen : do you know any datasets with mixed licenses, or a dataset that is licensed more openly than some of its content? It’d be interesting, and a bit scary, to see what happens to the record license in those cases.