(Warning: The author of this column is 57 years old and truly believes just about everything was better in “the old days,” including sports. For those young whippersnappers who disagree, beware of your eyes rolling too far back in your heads while reading this column, as they could get stuck there.) Once upon a time, not so long ago, many of America’s best athletes (brace yourself) stayed with the same teams for their entire careers. That’s right. They got drafted by a team, pledged their loyalty to that organization and that community, planted roots there, and stayed put. Dan Marino played on…