Imagine US companies suing China for not allowing them to operate there. People would say "China can decide what they want to allow". Well if China can decide (which they did first) two can play this game. Also TikTok says this ban is baseless. If USA's ban of TikTok is baseless, what base does China have for banning everything?
China's basis is that foreign companies won't respect their laws. What US laws has TikTok broken? Privacy isn't protected because an entire domestic industry has bought off Congress. Why can't a foreign company participate in the same?
Basically foreign owned companies don't have the same constitutional rights as ones owned by US citizens - these companies operations basically being foreign commerce is where the entity list powers are derived from.