I’ve been making maps for about 20 years. GIS. I don’t think it’s that bad. Though it should be titled the ‘Cities of The United States’.
Considering the data that is on it for the necessary scale to show that data, they did a good job.
Now, what I would have argued for was a map that showed basic geopolitical boundaries plus National forests, National Parks and National Monuments. BLM land and other public lands. As it is the map is too busy. But a simple public land back drop would have been pretty easy, and not make it any less readable.
I agree with a need for a locator map for at least North America. You might be able to squese it in above the great lakes if you cut the scale down to about 1:600,000 and remove about 1/3 of the cities.