Re: Good article
The difference is that around 1909 the Government of the US managed to pass laws which were designed to attack cartels and monopolists, and up until about 1990 these laws were occasionally effective (e.g. the Bell breakup).
Since the US economy started its long march to China, US governments have been increasingly worried about anything that might encourage US corporations to relocate abroad. I have the feeling that the current view from the Capitol is that cartels and monopolies are OK so long as they are our cartels and monopolies, while everybody else must have their markets opened to US businesses.