Amsdorf, I have experience with laser sights. That said, some of the people to whom you are showing some attitude make points similar to the ones I'd make, even if they don't have experience with them.
People are capable of studying things they don't necessarily have, you realize.
For instance, before I bought my motorcycles, I knew all about them through research (Cycle World, Consumer Reports, google searches). Same goes for my cars and trucks (add kbb.com and edmunds.com to the mix). It is quite possible to make reasonably informed decisions without "hands-on," at least with regard to quantifiable characteristics such as average maintenance costs, braking from 60mph, etc.
My personal take on lasers (I've had them on an SP101, a 442, and a PM9) is that they have some practical applications in SD for the average shooter; they are potentially very useful for shooters with failing eyesight; and they are good training aids.
I get on target faster using the iron sights; even if shooting from a retention position, the laser is only as fast as I can adjust my point, and to be honest with you, if somebody is so close that I don't dare to get a flash sight picture, I'm probably going to be too focused on moving and doing other things to actually acquire the dot before pulling the trigger.
I've seen a lot of shooters who don't use the laser for something which suits it very well indeed - dry fire. I learned to shoot J-frame DA in large part from laser dry-fire practice. I could tell those other shooters I mentioned didn't dry fire much, because their trigger control and sight alignment were horrible. The bullet only strikes the intended point of impact (dot), if the gun isn't allowed to move off target through the trigger stroke.
Spend enough time at a range, and you'll see little red (and sometimes green) dots dancing all over the targets and back walls (on occasion, the ceilings and side walls, too - that's an attention getter). You'll also see very steady dots, but in my experience those are not nearly as common as the dancing dots.
For shooters who accept that the laser is not a magical device, and does not work indepedently of good shooting fundamentals, the laser can be very helpful.
Pros:
Allows the user to cover a target while keeping a broader active scan;
Allows the user to aim from off positions, or behind irregular cover;
Helps shooters with poor near (sights) or distant (target) vision avoid the need to focus on two separate planes;
Is relatively easy to acquire in low light;
Makes a great dry-fire training aid.
Cons:
Does not help ID a target in lower light conditions (not a replacement for a light);
Does not guarantee a hit where the dot starts out (the shooter has to do his part);
Can inspire false confidence in new shooters;
Can give away user's presence and position;
May cause less experienced shooters to ignore iron sights skills;
Relies on battery or batteries.
Yes, I know, many things rely on batteries. For instance, my Bose A20 noise cancelling pilot's headset. When those die at inopportune times, I suddenly hear airplane engines, which is annoying. I then swap out the batteries (I carry spares in my headset case).
In a self-defense use, I doubt I'd have time to change a laser's battery - assuming I had a spare handy, which is extremely doubtful.
I've had batteries go bad on motorcycles and cars.
My watches have been known to sometimes stop; so have my cell phones.
A lot of people pooh-pooh concerns about batteries, and they have a point - most of the time, this won't be an issue, assuming a regular preventive maintenance / upkeep cycle is followed. Most of the time isn't always, though, and I have seen a lot of shooters who fall prey to the error of ignoring basics because their laser is "superior."
So, the laser is a potentially useful tool, but only if the user recognizes its (and his own) limitations.
