What is YC?
Y Combinator is a VC firm that specializes in investing in early stage/new tech companies and one of the first to do it on such a public scale. Their most significant successful investment is likely Stripe. Dropbox and Airbnb are other companies which had a lot of initial funding from YC
Not every article has to target the "everyone" audience.
What if we applied the standard to programming article? What if an article on rendering issues in mass effect and a patch in directx for the same had to include explanations for variables and for loops? It clearly weakens the article as there is value in getting to the point.
When you write hagiographical blog posts praising your teammates who are luminaries in the field, you write for the field. It's a sort of reverse shibboleth - you don't care for readers who know nothing and you increase the reader bond for those who do know. References (frequently to pop-culture) have a similar power. Terry Pratchett, for instance, does so very well with lots of things, including science¹.
Your invocation of the rule, actually, is an example of misunderstanding the purpose of a rule and misapplying it.