Sriram
You just can't resist rising to the bait, can you! You perceive an insult and reach for knuckledusters. I note that the figures you select come from a Wikipedia article which is headed with a warning that it may not be reliable and needs updating. And that was in October 2014.
Even so, you are still selective. The possibly unreliable article states that the birth ratio F:M in India is 1.12 and in China is 1:1.15. However, Japan it is 1:1.06 and Portugal 1:1.07.
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Be that as it may, I find your statement "Life is primarily about marrying and raising a family." rather touching and very human. I cannot think of anyone who would basically disagree with that. I think though that by blaming the career culture by itself may not be sufficient to explain the reluctance to marry.
My view about the sex drive in homo sapiens is that its primary purpose is not reproduction per se but creating a stable relationship within which the human infant, with its extraordinarily lengthy period of dependency, can be raised in safety. The behaviour described in Japan is - frankly - pathological. Young people appear to be rejecting opportunities to associate and become physically and emotionally close. I don't think that commitment to a career is the reason for this, I consider that it is possible that some environmental factor may be interfering with the sex (in its widest sense) drive. Perhaps (although I am not aware of any convincing evidence that pheromones are important inhuman behave) that the sheer variety and density of human sex pheromones is suppressing the sex drive in many individuals - well, it's a hypothesis.
I have visited Japan on several occasions and I love the place. But the human density is terrifying - watch the behaviour of commuters at Shinjuku or Ikebukuru stations: people behave like automatons. Perhaps other aspects of social behaviour are affected as well.