Deviates significantly from a normal user experience and results in a jarring experience for me personally.
I'm not interested in fighting with ridiculous scrolling games. If they don't care about testing their ridiculous scrolling plugins, I don't care about their product.
Sometimes I reach out to companies on Twitter or email telling them to please disable their weird scrolling effects. Nobody seems to care. I conclude that this behavior signifies a company that doesn't care about user experience.
By now I'm a little curious about these things, so I did a simple test of starting at the top and trying to scroll down to read the rest of the page. I can't find any way to consistently scroll to the third page. Just touching the touchpad on the second page causes an upwards scroll, even when I'm very obviously trying to scroll down.