How did wild cats actually become such a big deal recently?
Haven't they been around Australia for a few centuries already?
More people, more neglected cats going feral.
Also, cats can really only occupy more territory at cat walking speed, plus, if they have a good hunting area, they will stay there till their numbers outgrow the food supply.
Cities expand rapidly, till what was once "bush" becomes suburbia, putting habitat loss pressure on not only native animals, but also feral ones.
In any case, "recently" is a relative term----50 years ago there were baiting programs for ferals.