*pssst* did you know that the Dutch are pretty much in control of the US' economy?
The Chinese are just the next in line to buy US (and other) companies. Just like the Saudis are buying foreign companies. If they want to spend their money on US companies, so be it. You can still choose not to do business with them (if you feel like it), and these companies will still need to compete with other, US-owned companies. If it works, it works; if it fails, it'll cost China lots of money.
Perhaps you should look into the reasons *why* these companies are sold. Who is selling them, and why? Are they not making enough profit, or have the shareholders gone nuts? Apparently, it's much more attractive for the owners to sell a company (=lots of instant cash) than own/operate it themselves (=long-term cash, or loss).