The tails are considered a malformation because it's not normal for humans to have them, and they freaked people out who saw them. But the fact that some of these folks can manipulate the tails, and the fact that these aren't just blobs of flesh and cartilage but a well-designed functioning *system*, complete with pressure and vibration-sensing organs, and the fact that the tail was passed down hereditarily from generation to generation in some cases, shows that the DNA information for functional tails are still in us. Mostly not used or needed or expressed anymore, because we haven't needed tails in a very long time, but they still show up from time to time anyway.

Now, if we were 'designed' as we are, then why would we be carting around the genetic information necessary to produce a functioning tail? Because we *weren't* designed as we are, of course, but rather we evolved and adapted to fit our environment and method of locomotion, and somewhere in our probably distant past is an evolutionary ancestor which had a tail. Not necessarily a monkey or ape, perhaps a precursor to primates, but *something* with a tail, for sure.