I see what you mean. However, if owners kept their cats indoors, the population of feral cats would not be supplemented by escaped domestic cats and their litters.
The other thing that would help, though it's impossible to legislate, is if 'cat-lovers' would desist from leaving out dishes of cat food for the ferals, strays, and general vermin population to feed on.
PS - I just noticed the dates on the original thread. Yeah, that was a while ago. Thanks for responding just the same.