In Dungeons and Dragons 3rd Edition, a character's ability score is never rarely used. We only use it at character creation, to calculate the ability modifier. So, why bother having BOTH the ability score and the ability modifier? I feel the game would be easier to learn if we only had the modifiers in the character sheet (and called that the score). I know that some editions use the Constitution score, but that's an exception that feels tacked on.
I assume the designers are much more talented and wiser than me. So, why do we need separate ability scores and ability modifiers?