Part of the reason they hate China.
There is no reason for there to be an embargo on Cuba for example. This is a small country that was at one point backed up by an empire(ussr) that no longer exists.
And yet here we are. They are not a threat to anyone and yet any country that does business with them is punished.
If a country like China invests heavily into building a middle and upper class into countries around the world with its products and offers to build infrastructure they're solving two problems at once:
1. By sending their workers overseas they are making sure there is a constant stream of work. If job opportunities dry up in the mainland, the company can ship you to Mexico to work on projects there on a 1 year term.
2. By investing in those other countries and building up their domestic capacity, they're creating a loyal customer base that associates their products with affordability and quality, guaranteeing an ongoing revenue stream.
If they're successful in doing these things, the threat of losing American business is less meaningful when they're making the lions share of their revenue from countries with young, growing middle class like Mexico, Nigeria, India, Columbia, Phillipines, Brazil, etc.
While American companies respond to competition with layoffs, tariffs, and outright bans, other countries are selling to each other and building an economic base. The end result will be that an American sanction will be as harmful to a country China as a Jamaican sanction would be to Germany. They won't care and it won't make enough of a difference for them to care.