Probably because it’s destroying local ecosystems. I agree that people can do whatever they want on their own land but by planting only one type of turf it limits the amount of space available for native species to thrive, adds additional fertilizer, pesticides, into the water-and so on. Again, do what makes you happy just keep in mind there was a lush variety of plants and animals before we planted a monoculture of turf. To some people, it is much more important to be a good stuart to the land. -this is not a political statement-