This really should not be: I keep getting notifications that users are creating their own instances of Confluence and Jira, always by mistake. I then have to contact them to explain what they did and ask them to delete the new instance.
In the documentation I see that if we spring for an Enterprise license I can prevent this from happening, but I think that's really a pretty sleazy ploy to push us toward the added cost.
It should a) be way more obvious to users that they're making a mistake, and b) the ability of admins to prevent these mistakes should be free.