You’re right, the real distinction is on-premises vs off-premises, I should have made that more clear (although free software implies on-premises being possible)
The distinction is that companies that require HIPAA workloads aren’t going to upload their entire dataset into Google Cloud Spanner, which is not available as on-prem version, and which isn’t HIPAA certified.
So either we need an on-prem version of Cloud Spanner, Cloud Spanner needs to be HIPAA certified, certified to match German privacy laws, etc, or Cloud Spanner can’t serve these situations.