If China make bad products, then why do thousands of international companies make their products there?

I am not aware that there is a general opinion of China making bad products. There have been some problems, such as lead paint on children's toys. That does not mean Chain fails to produce quality products. It may reflect that the USA has extremely high standards that are difficult to meet at all times. Manufacturers in the USA have product recalls all the time. It's how everyone keeps their quality high. No offense is intended when a manufacturing irregularity is pointed out. It's just business.