Even more interestingly, if one is to press the case. The Video Game industry at least has something that resembles self regulation while the 2A folks refuse to accept doing even that much.
While I didn't particularly care for LaPierre's indictment against the video game industry, it should be pointed out that the gun industry isn't really allowed to self-regulate like the motion picture and video game industries because the gun industry already has so many legal regulations imposed upon it. Think about it, you don't have to have a federal license to sell video games, there isn't a list of features that cannot be legally incorporated into a video game, one needs no special license or permit to buy, use, or play a video game, and one needs not pass a background check to buy or possess a video game.
While you do have the ESRB and MPAA ratings systems, those are voluntary within the industry and not mandated by federal law. One could legally sell a M-Rated video game or R-Rated movie to anyone regardless of age, background, or mental status.
Your idea for a rating system for firearms really isn't feasible because they'd all wind up with the same rating: "Warning, this is a deadly weapon. Not suitable for use or possession by children, violent criminals, the mentally unstable, persons using mind-altering chemicals, or persons possessing poor judgement."
Also, as to your assertions that the firearm industry makes no attempt to self-regulate, that is untrue as well. Simply read the owner's manual that comes with any new firearm and you'll find all kinds of warnings about safe usage and storage, warnings about usage with alcohol or drugs, and warnings about keeping the firearm out of the hands of children. Some manufacturers like S&W and Ruger have even been known to engrave warnings right on the firearm itself. The fact of the matter is that firearm manufacturers have done all they can reasonably be expected to do to keep their products from being used negligently or criminally, but they simply cannot prevent everything.