Why are you putting up such an argument against lasers? I don't see anyone here trying to convince you or anyone else that lasers are some kind of super sight, the all that ends all, it's just some of the guys saying that they see a place for lasers in their use of defensive arms and why.
I see lasers as useful tools, I also view red dot sights the same way. Through the use of both, I've found that I prefer a target focused shooting style and lasers and red dot sights allow that with greater speed, accuracy, and range than iron sights alone. Red dots, lasers, and iron sights all have their place on handguns and can be used together, no different than using them on a rifle. Last year I shot in an IDPA style BUG match using my laser gripped J-frame and I smoked the competition thanks to the laser. Guys that usually shoot similar scores as me were nowhere close and the difference was that I was looking at my targets and could see where my shot was going before I got my sights lined up. I was making my shots while the other guys were still raising their guns and looking for their front sights. I see the same advantage when shooting rifles with red dots vs open sights. To me, the tactical advantage offered by being able to focus on your target instead of your front sight is great enough that it makes tools like lasers and red dot sights worth trying. I've found them to be a worthwhile addition to the tool box, again, not to replace iron sights, but to supplement them. As for night sights, I can take them or leave them, they are on several of my guns but I don't find that they offer any big advantage. I find a good light (hand held or gun mounted) to be a much more important accessory, I need to see and ID my target before I can shoot it and I can see a black front sight on a lit target.
BTW, I wear progressive bifocals, and they do make focusing on the front sight more difficult. I have to tilt my head back to find the sweet spot in the lenses and that makes my target even blurrier than it might normally be. This is another area where the laser and red dots shine, because I'm viewing both the target and the dot on single focal plane so that they're both in perfect focus.
“Never give in. Never give in. Never, never, never, never—in nothing, great or small, large or petty—never give in, except to convictions of honour and good sense. Never yield to force. Never yield to the apparently overwhelming might of the enemy.”