It's only natural for users to be interested their own builds. We are also building in support for other sources of builds, the only formally supported way to run a build right now is via Herald.
In our third party codebase, we designate an application as the "thing" that started builds which are scheduled and managed automatically by phabricator. I believe this is a common practice elsewhere in the codebase when you're at a loss for a real human identity and you need to apply some transactions.