The Beale Ciphers remain tantalizing to this day for two main reasons. First, the magnitude of the reward is impressive. $20 million is a lot more money than the average American will see in his or her lifetime. Coming into such a sum by simply solving a puzzle seems ridiculous.
Which leads to the next reason: because the Beale Ciphers are “simply” puzzles, it stands to reason that a person may have some insight that none of the previous cryptanalysts have had. There is a chance that any individual, professional or amateur, may stumble upon the correct answer. Because stories such as these are impressive, history has preserved them, which feeds our belief that we could be the next such lucky individual.