Bitcoins are fungible. One is valued and behaves exactly the same way as another. It's impossible to assign a lower value to 'Made in China' bitcoins.
Another way of looking at it is gold bullion. If you're buying an ounce of gold would you pay less for metal mined by slave labour in Zimbabwe than a modern mine with well paid workers in Canada or Australia? Of course not. There is no market for 'slave labour' gold versus 'ethically mined' gold. It's one market with one value across the board.
If you want to improve the plight of bitcoin miners in China then start an online campaign showing their problem and addressing their concerns. Would anyone care? Probably not.
REad this oped
http://cointelegraph.com/news/113897/bitcoin-violates-the-principle-of-fungibility
Bitcoin, among a slate of other cryptocurrencies, violates the principle of fungibility within money - that is, each coin's transaction history differentiates them from every other bitcoin in circulation. With the collapse of the hidden Evolution Marketplace, these coins have now been tainted, and services are wilfully denying their deposit into wallets held by exchange businesses.
