Well, that stuff spreads like the plague. It's no secret.
Oh... Well, for one, there are also not so vigorous varieties. And then it's still physically easier to cut a few ivy vines than to trim a hedge. That was what was wanted. Simple. You just shouldn't make the mistake of planting too many plants at the beginning, because ivy first takes root during the first year, before it gets going it can take 2-3 years. With large planted shrubs, you reach 2m faster. Also, don't plant them too close together.