Comment by efitz

When you start out with a store like git, with file system semantics and a client that has to be smart to handle all the compare and merge operations, then it’s practically impossible to migrate a large client base to a new protocol. Takes years lots of user complaints to and random breakage.

Much better to start with an API. Then you can have the server abstract the store and the operations - use git or whatever - but you can change the store later without disrupting your clients.