That's because it's a dirty secret. Most people selling you wealth building strategies are loathe to openly talk about how so much of it is based on "who you know" more so than "what you know". They might touch upon it incidentally in the course of their spiel, but it's either glossed over, or they don't have the level of insight/self-reflection needed to be able to articulate the value and cost (and indeed the pathways and mechanisms) of networking.