I don't mind having a policy of not dealing with countries which are undemocratic and/or have human rights abuses. But that would shorten the list of trading partners considerably, for example Saudi Arabia would be right out, as would Pakistan, Egypt, and so on. The US would have to buy $1.3 trillion of currency and Treasury bonds back from China and stop all trade with them. And no sunny holiday more trips to Thailand, military government, don't you know. Mexico? Well, drug war, corrupt police, forget about them. Nepal's a communist government, so strike climbing Everest off your bucket list. And India keeps having women and children raped and murdered, it's not government policy but is a widespread enough issue that we could call it part of the society. And...
And then we'd have to think about where to draw the line, for example Australia and most civilised countries have abolished the death penalty, and some like the EU won't extradite people if they'll face the death penalty back home - so should Australia not deal with the United States?
I'm good with that, I'm not sure that's the argument people really want to make, though.
It's also worth considering that the picture given to us of other countries may not be entirely accurate. Consider for example
this article about the United States. Most of it isn't lies as such, it's true but not the
whole truth. If the US can be misrepresented in this way by Arab media, is it possible that other countries are misrepresented by US and other Western media? Maybe just possible?
Now, obviously DPRK is a brutal dicatorship. But those other countries that fall a bit closer to that line of "let's not deal with countries like this", how about them? By what process will all this be assessed? I'm happy for it to be arbitrary and for most of the world to stop dealing with the USA, but again I don't think that's the argument people here are trying to make. Be careful where your own logic leads you.