I know of no one and no project that uses the bare git in a truly distributed sense that isn’t just one central repo with multiple users, or in rare cases a hierarchy of repos such as the Linux kernel.

This is also why the github/lab style services are so popular - it’s what people need. But I don’t think that’s a reason to keep this feature away from git itself. I don’t think many want to have to use github just to get this one feature, and as I said, for any repo hosting binary content (common) and using one or more central blessed repos (nearly universal) - it’s very hard to live without.

http://gitolite.com/gitolite/locking/#locking-binary-files

Locking is implemented centrally by gitolite. It would be nice if other services implemented the same mini-protocol.