I can understand in theory why they wouldn't want to back up .git folders as-is. Git has a serious object count bloat problem if you have any repository with a good amount of commit history, which causes a lot of unnecessary overhead in just scanning the folder for files alone. I don't quite understand why it's still like this; it's probably the biggest reason why git tends to play poorly with a lot of filesystem too…
See Fossil (https://fossil-scm.org/)
P.S. There's also (https://www.sourcegear.com/vault/)
> SourceGear Vault Pro is a version control and bug tracking solution for professional development teams. Vault Standard is for those who only want version control. Vault is based on a client / server architecture using technologies such as Microsoft SQL Server and IIS Web Services for increased performance, scalability, and security.