Long overdue in England as well. I have always owned a dog (at present chihuahua) and they have never been off a lead anywhere where the public have access, not even this little bundle of attitude.
The owner is always the one to blame (in my view) if a dog misbehaves, especially when it comes to fouling footpaths.
As for your final point, yes any dog can turn despite past behaviour not suggesting it will, but there is usually some human cause for this.
Leaving a dog with a stranger is just plain stupid, even those whome I leave the little blighter with I go on holiday are well known to him.