The present airport opened in 1968, and is known to the airlines as Huntsville-Decatur now, so those short hops ended then. The Jackson to Vicksburg isn't much better.
Southern Airways was scary I suppose, but they provided flights to small towns that now have no, or very limited, commercial service. Look at Columbus, Natchez, Vicksburg, Tupelo, The Shoals, etc. So Southern served a purpose. I suppose hubbing did away with small town commercial service for the most part.