This displays something like one of the homemade arms facilities the VC built underground. There were also hospitals, kitchens, meeting rooms, and everything else you need to get by. Thousands of fighters lived for years underground in conditions ten thousand times worse than this.
Americans are a surprisingly (to me) small percentage of the tourists. Hideously, one guy, one of the three Americans in this tour, asked if Ho Chi Minh was dead. Curiosity is good. Ignorant tourism is bad.