jumpies are new, utterly unique (Dat dial) and, as of yet, still poorly understood by the majority of players. This apparent hard counter better be an exaggeration, imo, because they can already be outplayed (and, going by recent regional results, they are)
The fact that they can be outplayed and can be beat does not mean they also can't have a negative effect on the meta. The exact same argument was made about the phantom.
We'll see what the next couple of regionals brings.