The hard taco is not a traditional Mexican staple. This is not to say that Glen Bell founded the hard taco. There is evidence that the hard taco shell existed in U.S. Mexican restaurants nearly a decade before they were used in Taco Bell. In fact, it is rumored that the reason that Taco Bell has hard tacos is because they stay fresh for much longer. Compared to soft tortillas, these crunchy taco shells can be stored for longer period of time.