What you feel doesn't matter to what is. Many were developed and made in China, but that doesn't mean they have the IP rights secured to sell in any or all markets where other patent holders registered the idea first.
> Actions and prior art that bar patentability under the Act include public use, sales, publications, and other disclosures available to the public anywhere in the world as of the filing date, other than publications by the inventor within one year of filing (inventor's "publication-conditioned grace period"), whether or not a third party also files a patent application. The law also notably expanded prior art to include foreign offers for sale and public uses.
https://en.wikipedia.org/wiki/Leahy-Smith_America_Invents_Ac...
Could be they used the publication grace period: you can be first to publish an invention publicly and then have a one year grace period to file and can use that publication as priority.