How is it a misuse of the product? Microsoft sell's that product with one of the features being touted as the ability to protect a document from being opened (or modified...more on this below...) with a password.
So you expect a file to be read only or hidden just because you check the file attribute box that says so? Where is the news article blasting MS for having such weak security that you can simply run attrib or change the attributes through the GUI??? It is non-news. These experts are just publishing this kind of stuff to keep their names in the media. It is FUD reporting, and we don't need it.

It is the responsibility of the user to understand how secure the product is and make sure that the security of the product matches up with the desired security of the content they are trying to protect.