Let's settle down here folks.... I have kids, the oldest is 13. A leash would've been a great option when he was 2,and took off while were at WDW..and hid...and security was called...and I thought my precious child was lost to me...we found him 1/2 hour later.... Get it?
Some kids are more active than others. Sometimes you just can't look constantly, you may turn to see a plane going over, or an interesting thing,and WHAM! if your kid is prone to take off, they do in that instant.
So what if dogs go on leashes, they work nicely for active toddlers also!

And the 'good parent' remark was unnecessary... My boys were both RUNNING by the time they hit 9 months old,and a stroller wasn't a place they spent much time in.... in fact, in many circles,its parents who *use strollers* to contain a child that are considered questionable...not by me, but by some, so it's not right to make parental assumptions based on tools we use to keep our munchkins safe....

I had 2 normal, incredibly , unbelievably,insanely,unstoppably,energetically,running type boys.... by the 2nd little prince,I got smart,and got a toddler leash,and used it when i needed to.
If I see a parent screaming at,or hitting a toddler ,I think bad thoughts...not a parent who's just keeping their kid close.....