I'm not the author, but I think they were alluding to the type of pride that results in negative forms of nationalism, especially when it's tied into ideas about ethnic states. Various nationalist parties (e.g. the British National Party in my country) are actually thinly veiled parties for racial supremacy, and the Nazi regime was born out of a myth of German natural supremacy. Not to say that all nationalism is like this, but there is a certain strain of national identity that cares much more about race or religion than culture or values.