Showing the version number to your visitors gains them nothing, so it's not there. Same concept as the rest of the XenForo UI.
Those same people most likely haven't updated their forum software to the latest if they don't know what the current version is.Why do you fail to see how Kier ??
Many people will think it is still in beta for a good long while, believe it or not many do not read all the threads here !!