Why do people in China always call spring mattresses Simmons?

Because Simmons used to be the largest mattress manufacturer in the United States, the early spring mattresses in China were all Simmons brands, so they were all called Simmons. A similar example is that all off-road vehicles are called jeeps (in fact, only the Jeep logo produced by Chrysler in the United States is Jeep). This situation is caused by the brand influence of Simmons and Jeep.