Well, their big selling point is that the interface is localized
in Chinese, which is only really relevant to Chinese developers whose English is not that good and who mostly interact with the Chinese technology scene. That they're hosted in China is also quite relevant for the speed comparison with GitHub.
So I'm not really seeing the nationalism angle here. Except maybe for the DCloud CEO, who complains that many good Chinese products aren't taken seriously due to a preference for foreign ones. I guess he's also not-so-subtly hinting that DCloud is another of those good products.