This ingores the bias of investors. The original post is quoting investors, so I don't think its a speculative bias. You seem to be suggesting to ignore the wisdom of "know your customer"--and for many founders/ceos investors are as critical a customer as any (equity is just another a value added product).
If we want to look at investors through the lens of a customer, I think that we should also acknowledge that sometimes you need to fire / turn down a customer. Different investors have different expectations, and compromising fundamental beliefs about how you want to run your business in pursuit of cash is going to be a horrible experience for both you and the investor in the long run.
People join YC to get the contacts and credibility to implement this strategy. But suggesting that they have the ability to implement such a strategy before having such credibility is flawed. The conditions precedent for it to be a viable ptactical are not in place. That's all I am saying.
Chelsea Clinton or Ronan Farrow doesn't need to do Y combinator if they want to launch a startup, they have their parent's rolodexes as assets on their balance sheets. But most people are looking to "raise social capital" along with raising financial capital. And to do this, other considerations come into play.
Of course, one can always use a calculated social transgression as a form of breaking into the establishment. That's also a proven stragegy, but its not without its own risks and is really beyond the scope of what started this comment thread. But it does need to acknowledged, so that's fair.