I would prefer associated password image for my private OpenStack setup. If it is public, Then obviously the answer is no.

Usually, my development team has undergone several VM creation and deletion. When they ask for new VM it is really a headache to create the new password for each VM. So I prefer to set the pre-defined password with all the images in the glance. So that I don't want to setup password every time. This practice only applicable since all I am dealing with private cloud.