History shows they were target because a racist administration was unable to control the narrative after the hostile atmosphere created in the aftermath of the Pearl Harbour attack. It has been stated instead of trying to act in a positive manner leading to protect all its citizens, the administration of the day decided to give in to bigotry and hatred and without any legal proof of wrong-doing against them sent its own citizens to concentration camps because they had Japanese ancestry. This is behaviour as shown by the then US administration was just wrong and cannot be condoned by anybody.
^Jollygood summarises the situation very well and succinctly here.
May I give you an example? Japanese parents, age 45 and 51, four children, grandmother age 72. All children are American citizen by birth, the others are Japanese citizen only by law. Instead of just virtue signaling, explain what you would have done with this family unit that's morally and ethically superior to what we did. Assume wartime conditions, of course.
The extracts you cited are interesting and do give an insight into both a wartime mindset and a 1940s mindset. The problem I have with them, and with your example above, is the word 'Japanese'. Whether or not these thousands of people are legally US citizens is an irrelevant technicality. Morally they are US citizens if they have settled and made a life in the country. What we do with your example family is to let them live their lives as normal, without fear of bigotry or prejudice or persecution, in a free country. Once you start labelling this group is American, this group is Japanese, then it becomes an abstraction and you lose sight of the actual people involved. And huge numbers of people at that.
I've been to Germany and I've been to Japan. The people there are people, just that. We may have different cultures and traditions, but fundamentally we are the same everywhere. In wartime there is forced conscription, and normal people are made to fight to the death against one another. Doesn't mean they want to do that. Doesn't mean that suddenly all these normal people across the world who happen to have Japanese ancestry become a threat. And it doesn't mean that we should label them as 'Japanese', when that is being used as a synonym for 'enemy'.
That's a quite interesting point of view. Another country does in Pearl Harbor, kills thousands of US Citizens, declares war n the US, and is universally understood to be the enemy, but citizens of that country are not the enemy. Since a country is comprised of citizens, I think a lot of people might have a problem with that.
Regardless of that, the link I provided provides the actual thinking and reasoning for these historical realities. So there is no need to shroud the desire to generate virtual signaling based on false pseudo-history. None whatsoever.