Of course not all dog owners are badly behaved.
However, a number of them give the rest a bad name, by such behaviours as:
a. Allowing dogs to bark incessantly
b. Dumping bags of their dogs faeces
c. Allowing them to roam free
d. Other ill-treatment
Point b is an interesting one. It seems to imply different levels of care. Those dog owners who DGAS (while their dogs certainly do), just let them carp anywhere.
Others bag it up, then drop the bag or (worse IMO) hang it in a tree. Are these people expecting a dog poo fairy to go round picking them up? Disgusting as it is, at least unbagged poo will eventually disappear. The bagged stuff will live on for a very long time.
It is hard to imagine the mind-set of these owners.
Round here, there was one resident in particular who put up a sign complaining of their garden being regularly shat in.
They put up a sign asking owners to desist.
Next thing, the lawn was covered in dog sh*t of all descriptions, bagged and unbagged.
Unbelievable.