The Edo period marked a time in Japan when they were more concerned with internal restructuring and growth, and wanted to limit external influence on the nation while they dealt with these growing pains. I don't know the history that well, but I think the Edo period began with the ending of strife between clans and warring factions, with rule becoming centralized under the Tokugawa shogunate. A lot of advancements and culturally rich work that are seen today came about during the Edo period, even with the isolationist policy.

I think with a country that has a rich culture, you don't need more influencing in order to grow. That kind of growth will see the culture lose some of its identity. A culturally rich society can continue to grow within the confines of its own rules and influences.