Its fine so long as we rejoice in the differences. The problems come when we become defined by them. That happens when the overiding arc that everyone agrees on, that unites everyone, begins to fail. Think on it. Increasingly people in your own society do not think of themselves as Americans. They are more and more defining themselves as african-americans, Hispanic-americans, anglo-americans, gay americans, muslim-americans, west coast americans...and so on and so on.
Its a very bad sign.