And notability isn't just for spam, the core difficulty with Wikipedia is that people disagree about what should be written in articles. The site only functions because of a masterful Jiu-jitsu move where we redirect heated arguments about what Wikipedia should say into heated arguments about which Reliable Source to cite.

That's the fundamental underlying reason behind all the rules and all the deletion discussions. It's not that the article isn't important, it's not that the content is wrong or not useful or that we don't want it. It's that Wikipedia would be pure chaos if it let people just write without sources, and the fights over content would never end.

Notability just boils down to "can we find enough reliable sources to write an article we can verify and stand behind?". Just quoting what authors of the topic say about their own work would of course fall a little short of what people expect from an encyclopedia.