Both light and laser are useful, I think it is hard to argue one to be more useful than the other unless given a specific set of circumstances, and we weren't. But, when put into the context of being mounted to the weapon (as the OP suggested) a laser is more inclined to that use. A light has far greater usefullness detached from the weapon (exception being long guns), and a laser isn't much use detached from a weapon. If I have to chose one to put on the gun, it will be a laser, and I will hold the flashlight in my hand where I can get more effective use from it anyway.
A weapon mounted light is a good tool, but not as good a tool as a handheld light, or a weapon mounted laser. If you can get all three, get all three, but we weren't provided that option.
As for the argument that a laser gives you nothing because you can point shoot without the laser. That argument assumes the gunfight will be as imagined, which it may not be. The very reason we have a firearm for self defense (whether in the home or elsewhere) is on the low percentage chance we will need it. So why back myself into a corner by not using that same logic in how a prepare for a fight? It also does not take into account the effect of greater accuracy. Can I get solid hits point shooting at close range, absolutely, can I get better hits with a laser at close range, absolutely. I will take the better hits if allowed to.
Just my opinion, based on my experience with lasers, weapon lights, and handheld lights. Your mileage my vary as the saying goes.