Because it reflects the fact that Wikipedia is currently written by the kind of Comic Book Guy who posts endlessly on Hacker News and edits Wikipedia. We are all Comic Book Guys to some extent when posting on the internet, but there are quite a few important deleted articles that are interesting only to non-Comic Book Guys. Inclusionism is about protecting their contributions from the depredations of rules lawyers who care more about "Notability" than whether a topic is included at all.