Perhaps debating which adjective best describes a murderer's motives is not the best use of our time. A drunk idiot who shoots two Indian engineers and thinks he got "two Iranians" is probably making some gut-level in-group/out-group generalizations based on appearances.

Balbir Singh Sodhi was another victim. Would that his Sikh values of protecting and aiding all human beings were more widely shared. Do we gain anything by calling it racism instead of xenophobia (besides, of course, a rhetorical club with which to intimidate dissenters)? Using the latter label might at least get Roseanna and Amy to pipe down.

I think it's possible for someone to see value in their culture and want to protect it without believing that other cultures and their people are inferior. The common shared language, customs, values, and beliefs of people in countries like Japan, Nigeria, Korea, Germany, or China are arguably beneficial to people there. And places like Ireland and Bosnia might show the cost of cultural conflict.

I didn't read the article, and the lines you quoted do not make me expect a sophisticated argument from Roseanna and Amy. But they specifically object to "Sharia law" and extravagantly claim "she wants that all here." Would they object so strongly to Padma Lakshmi or Dr. Öz?

If you ask me, Roseanna and Amy are wrong because we as humans have so much to gain from migration that it's worth the risk that we will lose something by letting our culture evolve.