It applies only to the Han majority in China, but somehow China's accused of some kind of genocide against its other ethnicities. Even the Dalai Lama stops at saying China's engaging in "Cultural" genocide, and not running around murdering all Tibetans. I don't support any kind of genocide, cultural or whatever, but you'll see no such distinction in media.
The policy also doesn't apply to urban couples who are both only-children, nor does it apply to the rural areas, and couples who's first child is a girl are allowed to have another child too.
Also, you're right India's entire population is younger. I'm focusing on the gender imbalance, which is present in both countries. If we're talking about economic advantage here though, it's funny, 67% of Chinese women are in the workforce there, but only 33% of India women are in their workforce. So India might have more women, but it's not like it's really an economic advantage to them.
But anyways, my point was, India deserves a fair chance at being the China like power in Generals 2.