This is, hands down, the least hostile leash thread I've ever seen on MDC! Wow.
I have no problem with them, and loved the harness we used with dd1. DH started a new job just two months before ds2 was born. We also moved when ds2 was 10 days old - lots going on. He really couldn't take any time off to help out with things. DD1 was two. DS1 was off for summer vacation, and was old enough (12) to help out a bit, but I didn't think he should have to give up all his time with his friends, either. Fortunately, there's a tourist farm just down the street from me. After the c-section, I couldn't walk a really long way, but I could walk to the farm, and go around the farm, so that dd1 could visit with the animals. I couldn't wear or carry ds2, so he went in the stroller, and dd1 went on the harness. She wasn't a serious runner (not like ds2), but she did bolt sometimes, especially near the pond and stream at the farm.
So, my options were basically to keep her inside all summer (baby arrived at the end of July, and I wasn't very mobile the last couple of weeks of the pregnancy, either), or put her on the harness.
She loved it. After we stopped using it (had started during the last few months of the pregnancy, to get her used to it, so it wasn't one of the bundle of changes with the new baby), she got it out sometimes and asked me to put it on her. She even asked to play "doggie", so she made that association at some point...but it didn't carry any negative connotation for her.
Over the years, I've used every combination of stroller/babywearing/harness that I can think of. Different combinations have worked at different times and for different things. People need to find what works.
Heck - over the last year, I've frequently commited the cardinal sin of AP, as I'm sure there are people who think dd2 is a bucket baby. I carried her around in her carseat quite a bit. She doesn't mind being in her seat, but she hates being put in her seat. So, if I was doing a fairly short errand (such as dropping ds2 off at preschool), I carried her in the carseat. It was hard, because that's not a convenient way to carry a baby, but it worked better for her. I'm sure lots of people thought I was being lazy and/or unattached.
I'd hate to see someone yanking their child around on a leash, but I've honestly never seen that. I have seen people yanking their child around by hand, though. It's not the tool that's the problem - it's the way people use it.