I tried really hard to ignore this comment, but here I am responding....
Before I became a parent, I felt this way as well. What kind of parent would put a leash on a child? Leashes are for dogs, the parents are lazy, it will damage the child, my child will deserve better, I will be a better parent than that, blah, blah, blah. Even with my first child I felt that it wasn't the best idea, but I started backing off with the judgments. Now that I am the parent of a busy child with autism who can run like a little cheetah, I completely understand why someone would make the choice to put a safety harness on a child. I personally haven't used a harness (or leash, if you prefer), but I have put a tall fence around my yard. I have safety latches on all my cabinets and my exterior doors. I use child safety seats, smoke detectors, life jackets, outlet plugs, and any number of other devices and gadgets to hopefully provide my children with a safer existence. I don't believe any of these things reduce or replace my responsibilities as a parent - they are simply tools that help me raise my kids. If you feel a harness is something that will help you keep your child safe, give it a try. It may or may work out, but nobody else's opinion really matters.