Kasaalan, WP:NOTABLE addresses the question of whether a subject is notable enough to justify an entry in Wikipedia. It is independent of whether a source is reliable enough for WP:RS, as far as I can tell from the WP:NOTABLE entry and its links. 

I agree with you on the writer's POV, but put that aside for now. I want to get the verifiability issue out of the way. If it's not verifiable we can't use it, and nothing else matters. 

WP:VERIFIABILITY is one of the cornerstones of Wikipedia. Is a citation to a book verifiable, if WP editors can't check it, because it's only in 3 libraries in the world?