What is your opinion with on the spot corrections to service members of a different branch?

I was walking down the sidewalk with a Sergeant Major in Afghanistan. He stopped a young Soldier from our unit and told him to put his eye pro on as it is a requirement at all time in Afghanistan. The Soldier said roger SGM, put hi eye pro on and moved out. A few steps later there was another Soldier from another unit and I stopped him made the correction and moved out. The SGM then told me he usually only corrects Soldiers from his unit.

Just wanted to get the opinion on this as I believe it is a huge part of the discipline problem in the Military today. Thanks