More likely you misunderstand the term ghetto, I refer you to the dictionary of your choice. Ghettos invole a level of compulsion, physical force, or simply economic or social pressures.
However, if ghettos are voluntary, how am I to understand the many derisive comments about most Jews having no religious values, just a bunch of secular liberals. They congregate only with Jewish secular liberals?
Intermarriage, around 50% in the Jewish community, they mail order Christian brides, who then settle in the Jewish ghettos.
This may come as a shock, but Jews associate with all kinds of people.
Obviously, you din't know any.