In my opinion they aren't necessarily a bad thing if you aren't paying a lot for them. A lot of people get very hung up on having laser sights. Maybe it's the cool factor from what we see in movies. The point is that they are no substitute for solid point and shoot aiming skills and not something to be relied on. I have a kimber ultra covert 2 that came with crimson trace laser grips. I overpaid for the gun as it was, the laser grips had a lot to do with it but I liked the way the gun looked.
One positive of having a laser is for dry fire training. With an empty safety checked weapon you can practice dry firing and keeping the gun on target. You will be amazed how much that red dot moves on the wall when you pull the trigger.