I don't believe the US is hung up on not improving. I think that's blatantly false and I think you're wrong about some of what you're claiming.
It's also a fascinating bit of hypocrisy, to say that the US is hung up on being right, and yet you feel free to bash the US while promoting the things others do right (you listed healthcare, education, roads). How does that work again?
The US does in fact improve. See: gay marriage legalization (something many of those supposed progressive nations you're referring to still lack). Body cams for police (a wide national interest in ending police brutality). Ending mass incarceration and the war on drugs (changes that are now supported by the majority of Americans). The ACA / Obamacare.
If you want to talk about roads, much of Europe for example has seen its spending on infrastructure plunge dramatically. The US is now spending more on its infrastructure than most of the countries you're likely to reference:
"Infrastructure spending in the euro zone has dropped to an average of 2.7 percent of gross domestic product, compared with 3.4 percent of GDP for the U.S. and 3.6 percent for Japan."
http://www.bloombergview.com/articles/2015-11-27/europe-has-...
It's almost universally recognized within the US that there are significant problems in both education and healthcare. You can hardly get away from discussions on these topics. What is occurring, is a slow moving national debate on what to do about fixing them. The US has a healthcare system the size of all of Europe's healthcare systems combined in dollar terms, which employs directly or indirectly millions of people - there's no scenario under which you're going to radically remake something like that in short order.
The US is a relatively complex, massive representative system, with local + state + federal systems that all play an important role and a total government budget so large it would be the world's #3 economy by itself. It's difficult for a government system that large to move quickly on almost anything. Imagine trying to get most of the countries in Europe to agree on major changes to their education or healthcare systems simultaneously, it's approximately an equivalent feat to remake education or healthcare in the US - both of which are heavily managed at the state levels.