For one, it's borderline fraud if users don't know what site they are on. Perhaps that's not the case in this situation, but there are many situations where it is the case. Secondly, it's a dirty move. Cloning a website no different than creating a cola, naming it "Cokke," copying the packaging and having it stocked on shelves next to the original.
Let me begin by saying there is and never has been a promise that the first creator of something on the web has rights to world domination. Its a naive and childish notion of "mine".
The position that an English based community can serve the world shows you do not understand that the Chinese community would never have immersed themselves into the current StackOverflow community. They need their own Mandarin based "community" that is run "within China". It is a great thing to see the Chinese programming community mature. They need their own forums for this to happen. Expecting or demanding they assimilate into the English language community shows a lack of understanding of how communities form and nurture themselves.
This issue is absolutely NOT about an "English based community" or a "French based community" or an "Arabic based community" or any other language based community, it's about conducting business in the global marketplace. My first startup was based in both Hong Kong and the US, so I'm saying this from a perspective of already dealing with both markets and with an understanding product development patterns in emerging markets.
The biggest question here is that some people in the global web startup world want to pretend they can hide behind language on the internet, as if it mimics geographic borders, which it increasingly doesn't. You operate in a global marketplace and if you clone a site or app using labels with mandarin or arabic it's no different than cloning it in a language that the application supports.
In general, I do not believe there is agreement on rules for a global marketplace. You play in China, you play in that market. You play in the U.S., there are different legal and cultural rules. You want to play in both, you get two sets of rules. Despite a desire by owners of intellectual property to see a convergent gobal marketplace with one set of rules, it does not exist.
Further, I do not believe that global "monopolistic" attitude is healthy. It does not create enough room for fragmentation. Fragmentation and boundaries (physical or otherwise) enables evolution and economic growth.
People complain all the time about China not being inventive enough and copying things. How do you expect this to change without going through this process. A process that clearly is just a repeat of what many established countries did to bootstrap themselves.