You do realize though that Japanese Society was stagnant until we broke their trade embargo with the rest of the world?, And that almost all of the change in the country has happened in the 20th century?
This is so deeply bred into the national psyche that the kind of government we see here is almost impossible. you are absolutely right about respect for authority and lineage. Also, that the importance of reputation and of maintaining the correct outward appearance has caused them to stay their course even when the people making the policy thought it was a bad idea?
The best example of this is the attack on Pearl Harbor. The younger officers believed that it was an unnecessary operation and that it would guarantee the United States entry into the war. A prospect that was teetering on the edge of not happening because of the extreme distaste WW1 left in the US's mind coupled with prominent Nazi Sympathizers (Charles Lindberg, Henry Ford to name a couple) The leadership of the Japanese Army and Navy also believed that it would have the same effect. However, because the junior officers felt it would be disrespectfull to mention this to the senior officers, and because the Senior officers would seem weak and loose face before the younger officers the attack was carried out with the results that were expected.
To get into a war the United States did not want and did not need, it took the entire senior level of government all chanting the same lies about Weapons Of Mass Destruction. In Japan, all it took was inaction and social taboo.
So to say that the Japanese political system is unresponsive to outside influence would not be at all surprising. To say that the old families that have always had a hand in controlling the country still do, is in no way surprising. I would be willing to bet a hefty chunk of change that many of them are descendants of Damiyos of feudal Japan.
And as for the cultural revolution that began in teh 50's and was brutally put down? Well, consider the lack of civil rights in Japan. There is no "Innocent Until Proven Guilty" The police are right. Even if they get evidence of you committing a crime in an illegal way, they can still use it. Also, in America, the social revolution didn't start with suburban whites, it started with the African American population who already were under the crushing yoke of Jim Crow that began the social change. Had Nixon been elected in 1960 the demonstrations by the black community would probably have been dealt with in a much more brutal fashion.
Going forward the real question is, can the new party actually accomplish anything? The article does not seem to think so, but who knows. The current crop of Japanese youth is far more individual than any that has been allowed before. This is based mostly on what i know of J-pop culture.
So in the end. there is some hope.