How many of the strays are aggressive is not the point, they are vermin. They carry various diseases, some that can infect kids, are traffic hazzards as well as a noise problem. Some do attack people especially if they have rabies. It's also the sheer volume of strays. I have never heard of people here kicking, stabbing or beating stray dogs, I think you made that up. Unfortunately people are far more likely to feed the pests keeping them alive longer and being able to breed more of the same.
Dogs can never be trusted they are sly crafty predators and all they are interested in is food. Looking after people comes before looking after mutts. Strange how people are not sentimental about the animals slaughtered for them to eat, it's always the doggies.