What an ignorant comment. There's evidence to suggest walking attachment devices for young children were used way back in the 17th century. It's possible that similar things were used earlier than that too. An early version of the modern one we are all familiar with now, started selling in the 1920s. Incidentally, use of it skyrocketed as more and more cars, faster cars and busier roads spread across the modern world.
And another thing, use of these leashes is common for parents of kids with disabilities. I have to use one with my son because his learning difficulties mean that he doesn't understand danger and if he gets frightened/overwhelmed he will often run away in a panic.
I don't like using it but I would rather have my disabled son safe and alive than not use it, and judgemental attitudes like this are the reason that I have to put up with unsolicited, nasty comments when I take him out in public; when I'm already dealing with the stress of keeping a child with extra supervisory needs safe and well.
Yup, sounds exactly like my kiddo too. And they are FAST.
It really feels like damned if you do, and damned if you don't and something happens to them.