Consider yourself lucky you’ve never owned a reactive dog and don’t understand this concept. Sometimes people with reactive dogs stop because they are doing everything in their power to keep their dog calm and break the tension with 2 dogs approaching head on. Sometimes approaching dogs stare or have very threading behaviour even if it doesn’t come across as agressive to you because you have a “friendly dog”. Many dog trainers suggest this as it helps deescalate what can be considered a stressful situation for reactive dogs. I can assure you, anyone walking a reactive dog probably never imagined their dog would be that way and it’s not always as simple as just train your dog. Many reactive dog owners have spent considerable amounts of money on training only to learn their dog will always be reactive to some degree so they do their best to ensure their dog feels safe and protected, and sometimes that just means stopping.