Say what you will about Deng Xiaoping, the four reforms were the best thing to happen to China since before the revolution.
But SPJ, martial arts were even popular during the cultural revolution, many people in China confirm this. My teacher and Omar's teacher experienced it and I even read an article with a student of Wan Laisheng that said pretty much the same thing. It is a popular story made up by some groups outside the mainland that martial arts died in the 60's and 70's, but many Chinese martial artists from the main land can assert that it was not the case (even though many martial artists were persecuted, I don't think anyone will argue that)