Because USA supposedly values freedom of conscience and actions (within a framework) of its citizens, something it says distinguishes it from China. If they're distinguished in this way then them acting differently is expected.
The rule is that if you arbitrarily block American companies then your country gets blocked too. It's called fair competition. If you open your country for American companies that are treated the same as your companies then we will do the same. Otherwise, no. The Chinese government and it's companies should not be treated as American citizens.
