Comment 6 for bug 1297130

Deleting the project causes authentication issues for the other services so it is pretty serious. (One needs to recreate the project and re-add the members to fix it.)

There's a number of workarounds that can be done today already (updating the identity policy (e.g. to disallow entirely or only allow a "superadmin" role of some sort to delete projects), creating a separate domain, using the customisation module to disallow deletion based on e.g. project name) so I'm not sure how much effort is worth spending on this.