The St. Louis Blues do not have the longevity, from a historical standpoint, that the Boston Bruins have. That is no fault of their own, but the Bruins have simply existed longer.
The Bruins have been around since 1924. They are also the oldest team in the United States.
So, with that longevity comes history. In a bit of coincidence, the Bruins were quite similar to the Blues in their early years.
Boston came in as an “expansion” team. They built their roster out of some players from the defunct Western Hockey League and others. Boston also made the Cup final in the first year they expanded the playoff format, though the Bruins had been around for couple years already, unlike St.