Possible explanation
I think we're looking at a geography problem.
A later paper from your source is here.
Here's a chart that breaks out the different technologies. Note the huge level of DSL in small nations, or nations with their populations mostly concentrated in small areas. DSL works best near centralized phone switching sources (I have DSL). This may not work well for much of the U.S.
Korea's level of fiber optics is impressive. There's a good article on it here.
Note that the solutions there were a bit more complex than simple "government vs. private."