Not true. There's plenty of information about how to maximise income by hopping proportional and scored proportional pools.
That is so, but I doubt that most of our pool hoppers are sufficiently savvy for that kind of strategy: they appear simply to be chasing past success, like punters trying to bet on a known result.
Ah, well then. That's not pool hopping, that's just being silly.
* abracadabra reminisces... ah yes.. the good ole days..