The on-prem requirement; probably most paying users with that requirement are not very price sensitive, since it's a regulatory requirement on them, or similar. They're also probably typically large orgs (so it doesn't look so expensive per user, if they would even consider it in those terms), and resistant to switching providers due to other requirements/processes anyway.
And that sucks, I do understand, I just don't think Atlassian will feel the loss, and stands to gain far more by jacking the price for the price insensitive customers who remain, as above.
