Robin
It is not just the risk of collision overhead but the added risks of multiple blind turns with high and low wing aircraft which are not needed.
Take my example of a striaght in approach. To get to the same point with an overhead requires six ninety degree turns and a desent as well.
I fly commercially and want my passengers to complete their journey as quickly as possible and as smoothly as possible so why would I want to lengthen the trip and add numerous turns?
Then we have the cloudbase issue. There are rules for cloud seperation flying VFR but how many times are you asked to join overhead and end up skud running to the overhead or when the cloudbase is below a proper OHJ level make your join at 1500 feet instead of 2000 feet?
Yes the OHJ has a place but to use it as a standard in this modern age is outmoded and has to increase the danger factor.
Pace