Sounds like they have been Americanized already.
Well, you have to realize that in most places, a "traditional gender role" means bare-foot and pregnant for the women.
One can move away from that and still not be a foaming left-winger. :D
You seem to have hit the problem. The problem may not be the men but the women who see marriage as an accessory rather than something higher.
Japan may be better off with these women not marrying and reproducing.