"Why should Israel be any different?" Because no western country demands that immigrants swear loyalty to the dominant ethnicity e.g. someone seeking to emmigrate to America does not swear allegiance to the White Anglo-Saxon Protestent USA, nor does a wannabe Italian swear allegiance to Catholicism. "If you want to move in Israel you have to be loyal." But loyalty to **what**, Boruch? In this case not just to "the state", but also to an ethnic group that will never, ever allow the oathtaker to join them.
from the article: Loyalty to the state is enough