Maybe some people don't have the eyes they once did.

Don't get me wrong...I'm a fan of iron sights on lever guns. However, I have a Marlin 1895 Guide Gun with a 1.5x Burris on it that really helps me get shots on target. I have a hard time focusing on the front sight on some guns now. With an optic getting my eye to focus isn't an issue. I just focus the optic to compensate for what my vision can no longer do.

I think that's a great reason to scope a lever gun.