Well, just for the sake of discussion, even though I do actually agree, let's just say that I think it needs the Exotic Ranged Weapon Skill.
Here is my reasoning. Unlike other mounted weapons, lasers do not have recoil. While mounting the laser is different then carrying it around, there are really two main difficulties in firing a laser. The first are environmental conditions. You cannot change those, at least not normally. The second problem is that you need to hold a laser steady, much steadier than a normal weapon. Especially since you can spray a bunch of bullets everywhere with any other gun. Lasers require the proper technique in order to keep them steady enough to actually cause damage, rather than just being a shiny light. Gunnery covers the techniques of most firearms, even things like flamethrowers, since they all operate on the same basic level. Lasers require a much more demanding set of skills and training to handle and use properly, which Gunnery does not cover.
I'm all for having this discussion, since I'm curious as to how things will turn out.