What's on the light sensor when? There's no shutter, it can just capture a continuous stream of light indefinitely.

Most people want a rough representation of what's hitting the sensor when they push the button. But they don't actually care about the sensor, they care about what they can see, which doesn't include the blur from the camera wobbling, or the slight blur of the subject moving.
They want the lighting to match how they perceived the scene, even though that isn't what the sensor picked up, because your brain edits what you see before you comprehend the image.

Doing those corrections is a small step to incorporating discontinuities in the capture window for better results.