" I mean, just think of large corporations that avoid paying tax or buy cheaply from sweat-shops employing child-labour."
When all else is equal...
All companies have these kind of skeletons in the closet. Chinese companies simply seem to have some more on top of those which everyone else lovingly owns.
Lack of regulation might be a reason when seeing this internally (within the country) - and then again, when all else is equal... But here we're talking about international events, and that's where you see companies A, B, C playing by the rules and company D (Chinese, more often than not) trying to cheat its way in.
No more than a couple weeks ago there was a story here on /. about Chinese students taking exams instead of the ones who should. After many, many, MANY such stories over the years one can't help but develop a stereotype.
From fake $ITEM to cheating in competitions, China seems on top of the world as count of occurrences.
I googled "chinese cheating": got 22.6M results, top results are about exam cheating.
I also googled "americans cheating", got 14.8M results, top results are about marital cheating.
Of course, this might not mean much, but it's a start. Anyone wants to send a research grant my way? :)