Answer the geomantic superstition, why old people are not good for future generations when they are old?

Old people are too old, especially those who eat and knock on bowls, which is very bad for future generations. It will ruin money and bring bad luck. A 90-year-old man who ate late, his son and daughter left in their 60 s, and his youngest son got leukemia. At the funeral of their children, the old man felt no sadness and looked as if someone else's child had died.