The problem is that saving throws have changed over the decades. In AD&D a Saving Throw was just what it sounds like: a quirk of fate that saved you. Having to roll a save was a very terrible situation, because failure was usually a punishing experience. Because of this, characters always got better at saving throws, indicating the character is better at surviving such experiences. The shift to modern games turned them into a mitigating factor, not an actual saving moment (kinda like Hit Dice stopped meaning "average number of hits you can take").