Of course they are. Like everyone else, they do what they're being paid for. It's the companies that outsource manufacturing to China that create the designs and set the quality standards.
You can pay more, and get 100% of your order QA checked and certain to work. Or you can pay less, and at best you will get 130% of your order because that will statistically ensure there's enough of your order done right in the package, but you sort it yourself.