The risk is not "I don't have a license because public domain doesn't exist", the risk is "the rights I have are revokable on a whim because they haven't proper

The risk is not "I don't have a license because public domain doesn't exist", the risk is "the rights I have are revokable on a whim because they haven't properly waived their right to do so". SQLite has a good track record but I can imagine another strongly religious developer taking advantage of authorship rights to damage some small EU-based social organization they strongly disagreed with; just an example. As for the weirdos, as I said SQLite has a good track record, but I'd think twice over a much smaller dependency. However, I've seen enough disregard for FOSS licenses in business to know the weirdos are few. I guess you either care about license minutae or you don't.