We Objectivists think in principles. as everyone should. We are fascinated by and focused on what principles are the right ones for a given context and how they implement. That is the perspective we bring to everything - finding and applying the proper principles.
But we are also emotional creatures and always are subject to emotions - often attempting to direct us to some preformed conclusion - often without any notion of accuracy. And, if we don't catch that erroneous process, we end up using our minds (improperly) juggling around princples to justify a conclusion that was improperly instituted in the first place.
I think we see a lot of that when Mark writes about Yaron Brook and ARI. He has a clear obsession with attacking them. He starts with anger and hatred and fiercely launches attacks using (or misusing) Objectivist principles. But, that doesn't mean that any given argument he makes is wrong. I found myself agreeing with many (but not all) of the conclusions in this article.
There is a property right that American citizens have in the legal structure of our nation and it gives us, using democratic government, the moral/legal right to establish and maintain a border and to choose who can come in. So, in that sense, I agree with Mark's observations of the problems Europe is having. And I disagree with Yaron Brook, and the many other Objectivists who - because they don't see that property right - will mistakenly apply other Objectivists principles and finding themselves defending open borders. And that makes no more sense than failing to see a property to ones' home and then trying to explain how higher self-esteem, or confidence, will turn around the angry, demanding, homeless people that have decided to move in.
In addition, prolitical correctness, which is so omnipresent in our culture that some aspect of it is ever ready to leap into anyone's mind when it matches a collusion, especially one improperly chosen. Look at how someone as far from progressivism as Yaron Brooks ends up calling people xenophobic because they don't want to see their culture transformed by massive levels of immigration of a people that don't assimilate.
I saw both sides of the open border argument getting caught up in progressivism's identity politics - aka tribalism/racism. If someone questioned my right to have a lock on my front door, I would not be swayed by an argument that I was just trying to keep people of color out of my house, nor would I be arguing that my door lock was for the purpose of keeping out people of different cultures or colors. Reducing an argument to an attack on someone as being racist or zenophobic is the demonizing technique progressives learned from Saul Alinsky. As a way of conducting argumentation it is, by itself, destructive to our culture (and the long-term, damaging to the mental well-being of the individual who abuses his mind in that way).
I didn't finish the article. It was long, and Mark's hatred for Yaron Brook and ARI comes through too strongly, killing my reading enjoyment.