What's the deal with bottle caps?

As the public sentiment appears to be moving closer and closer to a green environment, recycling grows ever more central to our quest to save the planet.Plastic bottles, aluminum, steel, paper, cardboard; all of this gets dumped into the recycling bin. Yet, for some reason, the caps of the plastic bottles have always been pariahs, not quite up to par with the other recyclables. Why do these small plastic discs not make the cut? While other, apparently similar substances get brought to reincarnation.
    This question gets highlighted even further when you take into account that basically any type of plastic can be recycled. However, the different types of plastics are what lead to this unfortunate predicament, as Signe Gilson states:

"When two types [of plastics] are mixed, one contaminates the other, reducing the value of the material or requiring resources to separate them before processing.”

Tops Off?: Why Some Towns Won't Recycle Bottle Caps: Scientific American

    These pesky pieces of plastic cause further problems. The lids can jam equipment, and causes processing delays. Also, the plastic bottles that maintain their caps do not crush as expected. When the plastic bottles are packaged into bales, they can explode as temperature increases, potentially hurting the employees.

Thus it is hard to believe but true: In most locales the responsible consumers are the ones who throw their plastic caps and lids into the trash instead of the recycling bin.

Tops Off?: Why Some Towns Won't Recycle Bottle Caps: Scientific American

    For the truly environmentally conscious, it can be painful to throw the recyclable plastic bottle caps away into the trash. For this, it is suggested to buy in bulk: why buy ten 20 oz soda bottles when a couple 2 liters would work just as well.