Because the thing about capitalism, is that its acolytes will happily sell the rope that they will be hanged with. To meet Wall Street's next quarterly expectations for rope sales, of course.
Companies want to do business with China, because there is money to be made, and their owners don't give a care about free speech or religion of people on the other side of the world.
And this is a good thing. It means that there's a lot of wealthy, influential people, who would really hate for there to be a war between two superpowers, despite the best efforts of nationalists.
PS. Countries spy on eachother all the time. If you think the US does not steal military secrets from its friends, and enemies, I've got a bridge to sell you.