This sample page shows how a document with a section that has content with no-contrast at all can still satisfy all Level A success criterions. I think its information cannot be "perceived" without assistive technology, so I guess this page is "only for people with assistive technology". I think that people that has good sight and no visual problem will not be able to access this content because they do not know even that there is something to see.
Of course this is an extreme of a problem that I've seen a lot of times. For me, as a visually impaired user, sometimes the low-contrast content is simply "no content", because I cannot perceive that there is something to see. This same problem occurs sometimes with input fields that have very low contrast with its background, so it is almost impossible to find them.