That is more of an argument for maintaining the Diaspora than anything else. In accordance with the above promise, I should mention that being confined to only one planet is almost as bad. Clearly, we should try to be involved with space colonies. Please note there is nothing necessarily unkosher about celebrating Thanksgiving by eating 15 pounds of butter. I'll treat the suggestion with the seriousness it deserves.
Assimilation has a number of facets.
The same in Israel, where the majority of irreligious secular Jews are quite content to let the most fanatical of black-hatted rabbis have full control of the Torah. This is obviously what G-d wants, as North American Jews were spared from Hitler's onslaught. Latin American Jews were spared, because their rabbis were generally trained and their synagogues supported by non-Orthodox movements in North America. Note that Britain, where the O rabbis have a bit more control of the Jewish religious instituions, got pounded quite a bit during WWII by the Germans, though G-d felt that British Jews were assimilated enough to prevent Hitler from launching a successful invasion. They were out of business by the time Hitler was on the scene, unless perhaps the Nazis invented time travel and went back to the past.