Ah. There’s a reasons for that, as told to me by a supply sergeant in the military. A lot of suppliers had a BEL (Basic Equipment List), which says all stock must have a minimum and a maximum of XYZ in order to meet government spec. Some large items, like diesel generators, have a BEL minimum of 2, but also because of their size and storage complexity, have a maximum of 2. So it order to get a new one, you must get rid of one of the old ones. But if you get rid of the old one, you are below minimum BEL, and could fail inspection or an inventory check, if it takes a while to get a new one. Large items don’t always “hang around,” but they get manufactured on demand, so the only way to get a new one is to be without one for a very long period of time. Thus, you risk failing inspection. The best way to avoid that is to keep two and never order any.
Military logic.
Google the older “envelope-stuffing scams” or “work-at-home envelope-stuffing schemes.” It was essentially a chain-letter / pyramid scheme disguised as home employment in the backs of magazines, supermarket tabloids, comic books, classifieds, and alternative newspapers WAAAAAY before the Internet. The classic version went something like you could make money at home, earn $500 a week stuffing envelopes, always stating “No experience necessary!” and tell you all you gotta do is send $1.00 and a self-addressed stamped envelope (SASE) for complete details!
You’d dutifully send your dollar and SASE, expecting instructions from Acme Envelope Stuffing Industries. What came back was basically, “HERE’S HOW. Place an ad saying’ MAKE MONEY AT HOME! Earn $500 a week stuffing envelopes! Send $1.00 and a SASE for details!'” and so on. When people send you a dollar, put these instructions in their SASE. And the loop keeps repeating.
So congratulations: you had just purchased the privilege of becoming the next layer of the scam. There were several names floating around for these, including “envelope stuffing,” “home mailing programs,” “mail order plans,” “money-making opportunities,” and sometimes simply “SASE schemes.” Law-enforcement and consumer-protection literature generally lumped them into work-at-home schemes or work-at-home scams. And they were everywhere before the Internet. The $1 was brilliant in a sleazy sort of way. It was too little money for almost anyone to pursue after discovering they’d been had. You weren’t going to call a lawyer because some bastard in Baltimore stole your dollar. But if 5,000 people mailed the bastard a dollar…