OK GM, but it kills loads of other plants/shrubs/trees.
I can see why ivy is shuddersome. For me, its not so much that it needs holding back or it will kill other plants, its more the gradual snaking, choking way it smothers things in its inexorable path to take over the wooooooooooooorld. Also, in a vulturelike fashion, how it grasps at dead trees so they look like ivy trees.
And also I read a ghostly comic when I was about 8 that had a story in it where lots of people were strangled by ivy snaking up through cracks in the pavement.
Not keen on it meself.