Which nation is that? I don't think it was the majority of the American people that agreed to the destruction of their culture. Just like the majority of the American people never agreed to letting in ten of millions of Third-worlders. Who was it that pushed for all this? Who filed the lawsuits in the courts? Who decided what gets shown in the Corporate Media?
The answers to your questions, are that liberals changed the culture.
Liberals pushed for letting in tens of millions of Third World people. Liberals filed lawsuits in the courts to legalize more and more explicit pornography, which in turn caused TV and movies to become more and more explicit in the themes of such programming. Liberals in Hollywood cast aside such standards at the Hayes code. Liberals decided to push homosexuality in programming. Liberals decided that the Corporate media would show things on TV and movies which would be unimaginable 50 years ago.
Likewise, the liberals being firmly in control of the news media, decided that they would present a liberal world view in news programming.
Most Americans are not in favor of all of these changes to our culture. A determined minority, determined to use the courts and the pervasiveness of mass media, decided to use these techniques to push their liberal agenda.