Well - much like Cher, not my cup of tea...but they got their loyal fans and those fans collect dolls and pay serious money.
To each their own and enjoy it. Tell people you collect chainsaws and they think you are either seriously mentally deficient or some kind of serial killer. I just buy what I like - but avoid the serious money stuff. Who knows - if you told someone in the 70s you "collected" guitars you didn't play - they would have laughed at you too...how many 50s burst were acquired in this era for a couple thousand and remain with those "collectors" and how many of those collectors retired comfortably with help of sale proceeds putting their treasure into hands of some current pop/rock star.