I've always had mostly negative feelings about Moose Johnston, mainly because he played the role of blocking fullback/selfless Caste solider so well that he more or less became the template of the White blocking fullback and made it easy to effortlessly shift other big and capable White running backs into that role from then on. A great example is Rob Konrad, who followed Johnston at Syracuse several years later. Konrad was so good as a record setting high school running back that Syracuse offered him their hallowed #44 jersey to play there. But unlike the previous 44s at Syracuse going back to Jim Brown, Konrad was used as a hybrid fullback/running back and wasn't allowed to be the feature back.
Then Konrad's fate was sealed when Jimmy Johnson took him in the second round, the same round Johnston was drafted in and again to a Jimmy Johnson coached team. Johnson is one of true godfathers of the Caste System, successfully taking his "formula" at the University of Miami and then implementing it with the blackest teams to ever win the Super Bowl at that time, but still with key pieces like Aikman, Novacek and Johnston. Eager wiggerish acolytes like Bill Cowher soon followed.
I'm sure Johnston could have been a successful NFL RB, but Konrad could have been a superstar, a Hall of Famer. He was big and fast with wiggle and shiftiness, he had it all. But of course like Johnston he too played the good soldier, and never got a chance to show what he could do with the Dolphins.