Why do rescues have silly rules?

Yes I hate it when they base their decision on your real estate. I like when they require that someone be home with the dog 24/7 or that the dog must be trained using certain methods. Any more I don't deal with difficult rescues. There are plenty of other sources where I can purchase a dog. These include kill shelters and pounds. I also have the option of purchasing a good puppy from a reputable breeder also.