One time there was this bug who got stuck inside a machine causing it to work incorrectly. This smart woman found the bug and taped it to a piece of paper as a joke. (Ha ha!) That bug was infamous! Soon, whenever a machine would stop working, people would be all, there must be a bug in it! (Ha ha!) Gremlins were right out. All the gremlins packed up their infernal make-it-break tools and trudged sadly home (which was inside a tree). They retooled and soon they were making not-very-delicious cookies that were insanely popular due to a pretty catchy ad campaign. Go figure. The bugs were not pleased with their ascension to metaphorical scapegoat and soon they lost all meaning at all, in the original sense of bug, that is. “Why couldn’t they have used buggy in its original sense (a small, two-wheeled horse-drawn carriage–in Great Britain–four in the U.S.),” all the bugs cried, uniformly, because if you’d seen one bug you’d seen them all. “Speaking of, we don’t even look like bugs anymore! Where’s our six legs? Where’s our exoskeleton? Where’s our antennae? Where’s our (sometimes) wings? Our compound eyes, our segmented bodies, and our thorax?”
Moral: It’s not easy being a metaphor.