As a note about fighting shows...
It can be entertaining. You take people who polished their skills, establish rules... or not... and see them clash to prove who's better. It's a sport like any other, though they wager their health on it more than most other sports. (Though there are other sports like american football that are harmful to your health, or practices like doping that can ruin your health even when the sport itself isn't that dangerous.)
The problem is when these privileged people force people who don't want to fight into such a contest. Slaves... desperate people... Tsuyoshi... This makes these self-proclaimed gods pathetic and evil. Unable to find joy outside of the misery they instigate.
That talk the couple and their daughter had reflects that kind of mentality. Nobody forces them to setup these fights, and this isn't a show of dignity. It's the exact opposite. It's demonstrating that they can only feel superior by looking down on those they force into degrading themselves. It proves them weak, pathetic and afraid. The higher they are on the social scale, the stronger these traits, as demonstrated by the geezer a few pages later.