What about the Romans?
Several geographic factors come into play. First of all Rome was inland and had no port. That meant it did not engage in trade (prior to the First Punic War) and was unexposed to new ideas from abroad. Secondly, the geography was relatively flat offering no protection from invasion. Once the Romans broke their Etruscan link, they fought their neighbors on a regular basis to survive, their citizen army proving superior to all adversaries. When the wars ended, the soldiers went back to their farms. Farming and fighting left no time for philosophy.