I've seen some Husqvarna and Stihl copies too, but don't know if they were current production. I suspect some of that is from making replacement parts - put enough of those together and you are making saws.
Your generalization is absurd - China is a big country with lots of different manufacturers and exporters, many different types of people. No doubt they do things for their own benefit, not ours, just as we do, but there will be lots of variation in ethics and the legality of what is done - also just like here. I would not buy a copy that I thought was unauthorized.
What you don't realize is that China is graduating engineers in huge numbers, while we pump out MBAs and host of other worthless degrees, and much of the state of the art stuff is designed as well as manufactured there (especially in electronics). The western corporations that sell that stuff are just sales and marketing fronts for the massive Chinese corporations that are the actual industrial capability behind it all. Many are aware that we lost our manufacturing capability, but not as many realize the design and engineering went right along with it. Only a fool underestimates the competition.
