I know why Jackie's number was retired, and it should be. Babe Ruth, however, didnt do anything more than be a good baseball player. He didnt speak for the game in any way, help it branch out or be a good role model. Ruth was one of the greatest players of all time, but thats it. There are plenty of guys who's number could be retired along with his.
As for Josh Gibson-
Baseball historians consider Gibson to be among the very best catchers and power hitters in the history of any league, including the Major Leagues, and he was elected to the Baseball Hall of Fame in 1972. Gibson was known as the "black Babe Ruth."[2] (In fact, some fans at the time who saw both Gibson and Ruth play called Ruth "the white Josh Gibson.") [3] He never played in Major League Baseball because, under their unwritten "gentleman's agreement" policy, they excluded non-whites during his lifetime.