A grocery chain with four hundred stores can afford to be wrong about a neighborhood.
One bad location out of four hundred is a rounding error. The other three hundred ninety nine carry it.
Dierbergs Markets has twenty nine.
So here is the cheap answer to the headline question. Dierbergs built a grocery business without leaving Missouri because it never had to leave. The St. Louis area was big enough to hold a family company for four generations.
That answer is true and nearly useless.
The real subject is what happened to the ground underneath it. The metro stopped growing. The city at its center lost about seven percent of its people in four years. One county on the western edge gained. Each store sits in exactly one of those counties.