You can find endless examples of things that are some illogical way largely because everybody believes that everybody believes something. For instance, why don't most buildings have 13th floors? It's not likely to be because the builders are all superstitious in this way. Instead, they do it because they're afraid that it would be harder to sell a building with a 13th floor in it, because prospective owners will be afraid it would be harder to rent or lease space on that floor, because prospective tenants/leasers will be afraid that prospective customers, employees, guests, visitors, etc. will be superstitious about it and feel uncomfortable going there. In this way, it's entirely possible that even in a society where nobody actually is superstitious about the number 13 any more, everybody still persists in leaving it out of buildings. (So why do cities frequently have a 13th Street in numbered street systems? Maybe city planners' incentives are different?)
Maybe “Nobody ever got fired because of the later performance of someone they turned down,” but they might wind up in one of those lists that circulate all over the Internet (and by photocopied and faxed documents in pre-Internet days) of famous people who got humorously rejected, like the Beatles being turned down by a record executive because guitar music was going out of fashion or something. Of course, many of the things on those lists are probably exaggerated or even made up out of whole cloth.