Those Chinese chopsticks are blunt mainly just because they are cheap. Better Chinese chopsticks tend to have the pointier ends with rounded tips. For cheap stuff like less than $1 per pack of chopsticks, the manufacturing will be more crappy. Also, Chinese do sometimes use metal chopsticks. There is nothing special about that. I had metal chopsticks, and IIRC, many schools also use these.

These are just eating utensils, people. There is no mystical reasoning behind it, just some different manufacturing processes based on established norms. It's no different than seeing silverware being slightly different between the USA, France, Russia, etc.