The most important reason in my opinion for carrying with night sights is shooting from dark to light. Dark room to lighter room. Or even from an almost purely no light room to a lighter room. This would be huge if the homeowner felt that they needed to hide from the intruder and then a must shoot happened. Woman hiding in a closet or under a bed from possibly several intruders and then found herself in a must shoot situation. That type of thing. Or even from my bedroom to the kitchen or living room. I leave a little light on in those rooms so it always looks like someone is there and up. My bedroom stays very dark because I have to go to bed by 8pm. But of course, this is in no way an argument against gun mounted lights.