Correct, however using a reversal ring is quite beneficial... holding your lens against the camera while focusing is a chore.If you do have a DLSR, you can always flip the lens around, hold it up to the lens mount (carefully), and have your macro shot magnified by a large large amount. The only negative is the extremely shallow DOF.
Never "HAVE TO" change lenses?!
You say that like changing lenses is some sort of chore. 8( I can swap a lens, with both end caps, in less than 5 seconds. Oh the horror.