Perhaps you misunderstood the concept of "melting-pot"
No, I was objecting to the word "inclusion". Native Americans have never been included, same with blacks. Catholics were despised at some point in time, and so were Polish, Italians and Irish. The locals didn't like Chinese either and slaughtered them. Japanese Americans ended up in internment camps. Jewish refugees from Europe were turned away in their thousands during WW2. Now Latinos and Hispanics are getting the short end of the stick. There has never been any real, immediate inclusion. It always took a few generations and it only worked if you were white and Christian. Let's face it: a large percentage of Americans are not open minded. They are effing racists and xenophobes.
In Australia, maybe the native aborigines remain separate aka segregated from whites.
Their culture was completely destroyed by the Brits and later by the Aussies. Much like that of the Native Americans over here. They separate themselves from the white society for good reasons and usually don't want anything to do with us. Unfortunately, alcoholism is widespread amongst them. Again, just like the Native Americans.
We (the alredy settled) are now one group (no matter that we usually hate each other too) and the newbies build the "other group"
When children of first generation immigrants are starting to look down on new immigrants, then you'll have to question the system.