If "shadow distance" means the distance within which light is cast, then call it "light distance" or something.
I would expect "shadow distance" to mean the distance within which shadows
Light falling on an object both illuminates the object and casts a shadow behind the object. In computer graphics, it's perfectly possible to have a light illuminate objects without casting shadows behind them. Actually, in terms of GPU load, it's probably easier that way. Maybe it's a limitation of Unity that lights always cast shadows, in which case this "shadow distance" thing might make sense to someone who knows the ins-and-outs of Unity, but it's still expressing it the wrong way around.
Shadows are not light. Shadows are the interruption of light. Light is additive, not subtractive. You start with a dark scene and add lights. You don't start with a white/saturated scene and add shadows, unless you're drawing in charcoal. When you're walking around your home at night, you don't think "I'd better switch on the shadows so I can see where I'm going."
Unless I totally misunderstood something.
I don't think either of us has misunderstood anything.