DD, maybe you underestimate the affect of the American economy on the rest of the world. That's why people from other countries comment about the US economy.
Trump has caused a stock market crash, affecting pensions and investments worldwide. Tariffs are likely to hurt American consumers. Trade and economies that have taken years to set up have been unbalanced. America has lost the trust of a lot of countries who are now looking for alternative markets. Consumers outside America are boycotting American made products.
Trumps goals to streamline America's economy may be the right thing to do but it seems like he was trying to do it overnight.
If you are a Trump fan, the 'America first' motto probably sounds great but he seems to be punishing everyone else for Americas problems.