According to Osho, the 'twenty-four' is not a mystical number but a sociological stop-sign: when a supreme genius appears—like Mahavira—followers feel the ultimate has been uttered. Fearing the disruptive, anarchic nature of future genius, they close the doors, canonize the chain, and declare 'enough,' choosing security and order over open-ended, living growth.
People stop at twenty-four not because of math, but because after a brilliant teacher, followers get scared of new, disruptive wisdom and lock the list.