Make Internal Links Scroll Smoothly with JavaScript

There’s an interesting article over at Sitepoint about using Javascript to enable jump links to scroll you smoothly down the page to another location. According to the author, the reasoning behind this is that:

When they’re navigating through a long document, users often are confused or disoriented when they click a link that jumps to another location in that same document.

Are they? Based on what evidence? In all the usability testing I have done, never once has a user complained to me that having a link take them to another location on a page is confusing.

Where is the evidence for such a sweeping statement? As Keith has mentioned over at Asterisk*, the web is strewn with generalizations such as this, passed off as rules to be abided by, and backed up with no empirical data whatsoever.
Am I really expected to go to all the effort of recreating the script without knowing in advance whether it’s going to be any good or not? Please. My time is way too precious. A List Apart does this much better, with numerous examples in every article. Take a tip from them and let me know what I’m getting.
My own testing has shown that users often actually like a list of jump links at the top of the page so that they can quickly (i.e. immediately) get to the content that is relevant to them.
Okay, so the article didn’t make such a great start. Disregarding whether it is a good idea or not, it sounded pretty intriguing to me. If something is interesting to me on the web, I want to take a look at it–I want an example or a demo.
Well, I browsed through all three pages of the article and could not find one example to demonstrate the technique in action. Maybe there was, and I couldn’t find it, which says something in itself.