The JP community is more organized because gaming as a hobby / recreational activity is taken more seriously in Japan. That and as a society they take a fundamentally different approach towards respect to group time and dynamics.
The DF on Japanese servers isn't treated as a testing ground and the "who cares it's just ----" mentality isn't prevalent because while the level or ease of content may be insignificant what they as players are treating with value
is your time an issue that we currently have in the western community.
Incidentally if the latest unofficial census is to be believed Tonberry has the lowest Savage Alexander clear rare of ALL
Japanese servers while also having the largest western presence.
Food for thought.