On the one side of the scale is people enjoy it. Maybe that's enough. I feel similarly about drug policies (that is, people want to use it, consequences are on them, not something that should be forced on them by the state).

I also think it's legitimate to say if there's a problem, policy should reflect that problem. The idea that it's about protecting American money is probably fair too. But those aren't really arguments in support of tick-tock. Those are arguments that others should be included if there's legislation. I would love to see something passed that actually protected privacy universally. A hope for constitutional protection there was one of the casualties of the Roe v Wade overturn.

Last thing... a nation protecting it's interests is pretty legit in terms of legislative justification. One country protecting it's industry is very common and something both countries in question do all the time. Protecting from foreign interference is a pretty standard requisite for sovereignty. If you want to criticize US for not respecting others, I think you've got plenty of evidence. That's still different than saying a county shouldn't take steps to protect themselves.