At the risk of being controversial...
...I can see one subtle difference between the two.
The NSA (there are other equally as nefarious agencies in the US, but I'll group them under the NSA umbrella for brevity's sake) wants backdoors into everything so they can spy on you and everything you do, irrespective of that annoying concept of due process. But, at the end of the day their hearts are in the right place, it's just they're being totally and utterly evil about it in every conceivable fashion. Any advantage they want is simply to disable the enemy in any way possible. Of course their methods are wrong and despicable, but since when did that ever stop a good spy agency doing whatever their dark hearts desired. (And if some of that tech should just "accidentally" fall into commercial hands then oops!)
China wants to backdoors not only to spy, but also to gain competitive business advantage to their state sponsored businesses and other businesses that will provide a competitive advantage over everyone else in roughly equal amounts. Much of the information gleamed will almost certainly make it's way to China's "Independent Commercial Business" (which honestly have no connection to the ruling Communist Party whatsoever...) as a simple matter of process. For them there'll be no accidents, it'll be methodical and deliberate.
Hence the subtle difference to me.
So the way I see it is that the NSA are only 99% evil, China's hitting the five 9's.
And GCHQ and our English Secret Service Pals? Well - we all know us British play the best evil characters in movies for a good reason...
OK, now please, downvote away!