Good point.
That is exactly what I wanted to point out with my statement about racoons. In most inhabited areas, free-roaming cats fill in the ecological niche that other similar predators already inhabit. A few cats do not significantly increase the impact that existing predatory wildlife already has. They basically do what a few more racoons, owls, possums, foxes, you name it would do. Since wildlife populations naturally fluctuate, the comparatively small increase in predators does not matter. Furthermore, pet cats do not fully live off wildlife. After all, they get fed at home. What they kill for play is a negligible fraction compared to what a single racoon, fox etc would kill for food per day.
Different story in areas without those predators, such as the example you mentioned

. If I ever move to New Zealand I will think of you
But at least in Europe and Northern America, above mentioned predatory network already exists, so that cats do not significantly shift the biological equilibrium.
You know what, I think this would be a great topic for Del's assay

What a funny discussion on a fish board
HarleyK