I think they were trying to say that we are choosing to segregate ourselves more publicly, not that there is a return to government mandated segregation. Which is somewhat true, but not necessarily dysfunctional or unhealthy. There's a really interesting study by Robert Putnam from Harvard. Here's part of the abstract relevant to this topic:

In the long run immigration and diversity are likely to have important cultural, economic, fiscal, and developmental benefits. In the short run, however, immigration and ethnic diversity tend to reduce social solidarity and social capital.

I'm not going to use silly words like good and bad, some of us do choose to segregate ourselves, but we appear to do it more typically because of the desire for community and safety, as opposed to hate for the other.