As a gimmick, and a novelty, I have to give it to the business owner. He has cornered a segment of the market, that obviously wants it. There is no reason, whatsoever, anyone should go in there expecting a healthy meal. it clearly states that the meals are, well, bad for you(to be PC/DC Friendly). He has all of the "nutritional information" posted with all menu items, and people know what they are doing.
No one is forcing people to patronize his restaurant. He has a corner of the market, that appeals to the like of the Challenge Eaters, like Addie referred to, and obviously enough people(the lovers of excess, college kids, etc etc etc...) to have kept the place in business for as long as it has been.
If you are going into a restaurant called, "The Heart Attack Grill", and knowingly order something that states the calorie count(among other things), orders it, eats it, and has a heart attack, IMHO it is not on the owner to shut down because of it(
as is being requested)
Is the govt going to go around asking business owners to go around and shut the doors on any place that sells booze, or tobacco? No.
As gross/scary/sickening/excessive as it is, he's not breaking any laws.