The story I've heard is that it was originally designed for incandescent drop-ins where you actually wanted the bulb to stay hot and you didn't want to transfer all that heat to the body where it would burn your hand.
That actually makes a lot of sense. I think this is the same issue with replacing house lights with LEDs. The fittings are usually well insulated, since an incandescent could burn down your house.
Has anyone else considered wrapping the drop in with a thermal pad, the kind commonly used on GPU heatsinks? They seem to be malleable and can compress when pushed into the housing. This would eliminate any air pockets between the pill and host. I found some on eBay for a couple of bucks, but I'm concerned that the thermal conductivity isn't good enough to make a difference (2w/mk).
Any input?