The not_scalable flag shouldn't prevent a quickstart from being created as scaling, just warn the user it may require additional work to implement or not work as expected.
Fix in https://github.com/openshift/origin-server/pull/2832
Commit pushed to master at https://github.com/openshift/origin-server https://github.com/openshift/origin-server/commit/9a545a3554113854088467f30529db115d605625 Bug 971147 - make not-scalable a recommendation
Tested on devenv_3360, user can create scalable quickstart now, and the warn message can also be displayed correctly, so verify this bug, thanks.