This was location of most of the original colonies, and it doesn't make sense for any other region to be more urbanized and industrialized. The US didn't inhabit the entire continent at once, instead, they slowly made their way across. Industrialization takes a long time, and it only makes sense that the longest inhabited part of the country would be the most industrialized at that time.
The Supreme Court ruled that the evacuation order violated by Korematsu was valid, and it was not necessary to address the constitutional racial discrimination issues in this case.
