Earlier dictionary definitions of "drone": 1. A male bee, especially a honeybee, that is characteristically stingless, performs no work, and produces no honey. Its only function is to mate with the queen bee.
2. An idle person who lives off others; a loafer.
Why is the sky full of Wallys?
In an effort to save money, the PHB bought the "trojan robot" from the company's competition, with the result we see here. Actions and Attitudes have Consequences - that is the most difficult lesson for anyone to learn - in the PHB's case however, hmmmm....suspect that later on Wally and Dilbert will get together and fall down laughing at the state of the PHB...