There have always been folks who collected weird things. Of course, the idea of what is a "weird" thing to collect is completely subjective. To me, it's odd that lots of people collect modern super hero comic books, since they take up a ton of room and are printed in such enormous quantities that few ever seem to appreciate in value. But collectors of anything are a strange and dedicated breed, and trying to understand the appeal of many collectibles might be futile for a person looking in from the outside.
But there are some things that people collect which might seem unsavory to a majority of folks, not taken with the same collector bug. Things like: