GL, this article is no doubt interesting. Perhaps the "epidemic" was fueled by hysteria of sorts. However:
1) Just because claims decreased in AU doesn't mean that repetitive use of a mouse of keyboard doesn't cause pain.
2) Most people now realize that using mouse/keyboard over and over again all day can cause pain, so they now take breaks or have changed their habits - this again could be the reason cases have dropped.
3) Repetitive behavior such as in factories, tennis players, carpenters, etc have known to develop problems related directly to their work.... are people who pound unusually hard and frequently on their keyboard exempt from this?
ps. interesting debate topic.