[Kluggy]

It's absolutely because of inertia. Cutting a tarball is a very public indicator that the software is ready to be used. A git tag or branch doesn't have the clarity of "use this" as a release tarball does.

That said, this is absolutely going to be changing now. We obviously can't keep relying on tarballs anymore. We'll find a new normal that will work for a very long time until some other critical issue arises and the cycle repeats.

[kzrdude]

We can use tarballs - they are useful as signed artifacts, but only if we verify that they are reproducible.

[lupusreal]

If you're going to download both the tarball and the got repo and verify the reproducibility of the tarball, then why bother with the tarball at all? You already have the got repo.