This is something like a broken windows fallacy. Go after anything that moves and try to extort some money. I live a couple of hundred miles from Detroit and ran into a old guy in town here who retired from a parts factory in Detroit and abandoned his house. Every month, he would get a threatening note about doing something with his property. He explained to me that the sales value of his home was less than the the cost of bringing it up to code to sell it. This is one of the reasons houses are abandoned. He sent the city of Detroit his key and wrote a letter to Detroit saying that he had given Detroit his home. He kept getting letters. It might sound caring, upstanding, and forward to have everyone bring their house up to code but it has to make economic sense to the owner. Also, some people can only afford a fixer-upper and will fix their home as they can afford it. Such legislation makes all this less possible and leads to abandonement; all with the best of intentions of course.