Japanese culture is very honor focused. This by itself is going to distort the response to the signal. The signal in Japan is tied to the economy - fewer jobs for salarymen means fewer able to live the salaryman ideal. I take sangha's point to be that America doesn't have to contend with those cultural vectors.
Here's what I see going on and maybe this can reconcile the two viewpoints you guys are advancing. The rise of women's liberation in the US occurred much earlier than in Japan and our culture has been less rigid in response to every change that has happened. What we're seeing in Japan looks like what we're seeing in the US but the root causes differ. In Japan this issue is being driven by labor market changes rippling out into the sexual market place. In the US, the primary driver of this phenomenon is the advance of feminism and this is rippling out into the sexual market place. Feminism is taking root in Japan and the changes there are following the trajectory pioneered in the West, but that trajectory is shallower in effect and not as far advanced, so the effect size in Japan, while still present, is small and it's really labor market changes driving the issue there.If it can happen to them, it could happen to us. In some ways, we are trending in that direction already with the rise of internet porn and the "failure to launch" culture.
In Japan, it appears that a lot of women are willing to give up their careers but they need a salaryman in their life to make that happen. The guys who can't be salarymen are withdrawing from having to face what they see as failure and the women are not lowering their expectations.A lot of women simply don't want to give up their careers for the hassle of raising a family.