Currently, when creating a RAID device, the default is striping for optimized performance. I think mirroring for redundancy is a better default choice -- if people want to put their data at risk, the should be able to, but let's default to the data-protection choice.
This bug appears to have been reported against 'rawhide' during the Fedora 19 development cycle. Changing version to '19'. (As we did not run this process for some time, it could affect also pre-Fedora 19 development cycle bugs. We are very sorry. It will help us with cleanup during Fedora 19 End Of Life. Thank you.) More information and reason for this action is here: https://fedoraproject.org/wiki/BugZappers/HouseKeeping/Fedora19