IMO the actual big draw of America was that it was a nation of laws and ideals, rather than a nation of men. Those ideals are that there exists a fundamental right to life, liberty and the pursuit of happiness for every person. The problem with the idea that we can all join a community that agreed mostly with ourselves, is that some people mostly agree that some humans can be considered property based on the color of their skin. Or that women should be subservient to men. Or that the final solution to their problems is that one religion or ethnicity should be excluded from their society. These people exist today, they were not defeated in the Civil War or WWII. See: Charlottesville.
The process isn’t about forcing everyone to follow what you want. It’s to force everyone to permit everyone else the fundamental rights protected by the Constituiton. We know for a fact that when you let people organize into autonomous groups based on their own preferences, some will tend to organize into a group that is at stark odds with the idea and ideals of America. We’ve seen it before with disastrous consequences.