Back in the day when my Dad flew...they turned on their landing lights at the outer marker...I was told the reason for this was that they were very expensive! I currently live under the approach for Hobby Airport and Sugarland Airport...on clear nights the planes on approach to Hobby are lit up like Christmas trees...and visible from 40-50 miles out. Is this some type of new regulation, or have landing lights gotten cheaper to the point that the more visible plane is the safer they are?
Remember there are alot more aircraft flying around now than back then, that would have alot to do with it and so from a safety standpoint, better to be seen from afar.