It's actually because the focusing is linear that the focus scale is compressed near infinity and more generous at close range. This is can be a problem for macro lenses which cover a much greater focus range in the same focus throw, the range near infinity becomes very short. The only way around this would be to replace the linear helical focus action with a non-linear focus cam. The gradient of the cam would be shallow near infinity so the focus scale stretched out, and would become steeper at close range. However, focus cams are harder to make, can be less accurate and more likely to have some slack in the focus action, so are not often used, although cams are common in zoom lenses.
