At least on an initial response to your question, I think my response is conflicted. (Unsurprisingly?) This is actually one of the fundamental questions I'm trying work with in this book, this question of how we can passionately love and defend and invest in a culture, seeing it as valuable and worth protecting -- while at the same time, those emotions and investments are exactly what lead to young people joining the Tamil Tigers as suicide bombers, and to gentle elderly members of the diaspora sending money back home to buy guns. I don't think shattering the culture as a way to universal peace is either possible or desirable -- too much is lost, including much of what makes us human. But at the same time, I think my book is trying to create a wariness of over-investment in one's culture / race / etc.
Maybe that's the same thing Apphia is saying, when he seems to be arguing that we need to put the universal human values ahead of the particular cultural elements -- but the force of his argument goes a lot further, I think, that I'm comfortable with, and runs perilously close to cultural obliteration / genocide. And of course, that genocide is weighted in certain directions -- it's not a completely free mixing of culture creating lots of little beige babies -- the imagined post-racial future reads as an essentially white one.
I suppose the short form of all that is that Appiah's come down fairly firmly on one side of this debate, if I'm reading him correctly, and I'm still trying to walk the tightrope (and pull everyone else up onto it with me.) A perilous place to stand, but the alternatives seem worse!
A quick intro to Appiah here: http://en.wikipedia.org/wiki/Kwame_Anthony_Appiah