We have a situation where we have 100's of short term projects per year, that last a week or two (we currently use SVN for them). The code is rarely reused or accessed again. We know we can zip up and archive the git repositories, but not the project data in Stash. We don't want to end up with a stash display of hundreds of inactive projects.
This would also apply to projects that are EOL, but may need to be retrievable to protect our IP.
I know we could hide the projects, by making them read-only to one user, but they will still be there, in the databases.