The idea of open markets is that no player is given favorable treatment by the government. If you allow a player that comes from a country that treats its citizens as human farms, I wouldn't call that open markets.
The two statements just don't logically follow. A better argument would be that the US, in an effort to improve human rights, sets a minimum threshold for market participation at the level of nations. Unfortunately, that's not the argument being made.
Open markets mean what it says on the tin - markets without barrier. Saying, "We're barring actors for entering the market for reason X," means closed markets even is X is "treating people poorly."
Open markets mean what it says on the tin - markets without barrier. Saying, "We're barring actors for entering the market for reason X," means closed markets even is X is "treating people poorly."