Its not so much that its slow, but that it relies on a voluntary network of other devices to pass on the signal, which is a bit like expecting Rabbit phones to work.

If it were combined into an RFID device then it might make commercial sense, even if it does also advance Big Brother.

On the other hand, I could do with such a thing at times, not to find my car keys, but to find my car.

Does anybody really need a VERY SLOW wireless technology?

That's what ZigBee is. The advantage is, it will work continually for a year or two. At least, that's the plan...