I think any one country becoming the global "superpower" of AI is unsettling.
As utopian as this sounds, the only way AI's evolution can be a positive thing is if we develop it collectively to create a post-scarcity world. It's the fight for resources in a resource-scarce world that fuel such competition in the first place.
Approaching AI from a competitive angle could end in humans being killed off.
This is my point actually. Both the US and China are competing countries and have different values they abide by. To have China as the leading power in a technology that could impact millions of lives at once should be worrisome. This is why I don't really mind the fact that Facebook, a company that is highly criticized, is working on AI development. I am not sure about the potential benefits of the company's initiative but I try to remain hopeful that its findings will be a substantial response to the Chinese technological expansion.