What about unexpected changes in the real life league? Let's say we see a dramatic decrease in the number of fouls called per game once the season starts, for whatever reason. But the game has already shipped in its "NBA experience" settings, which were based on last year's fouls. Sliders can help to lower the number of fouls to be more in line with what we see in the real game, in spite of the developers getting it right initially, based on the previous year.
Obviously that's an extreme example, but I'm just trying to prove the point. Customization options is not meant to be a crutch for the devs, but rather to enhance the experience for the user.