I contest those are not "real challenges" in the way you are implying. Sure they might be on the mind of inexperienced founders because they are suddenly relevant and novel, but they are also quickly solved by bringing in experts or firms. These are superficial challenges and only become "real" if they are snowballing with more fundamental issues (lack of growth, money, market fit)
IMO, that's almost like saying "Building the app isn't a 'real challenge' because we can contract it out to IBM."
Yeah, you can hire "experts", but it's expensive. Having some basic knowledge of how things work can postpone hiring experts until the company can actually afford it. Want an expert HR person or an expert shipping/receiving guy? That's $150k each per year.
I mentioned this in a post just yesterday. The way YC (and VC in general) encourage companies to scale quickly at all costs increases dependence on VC money because it encourages companies to spend extra money getting things done/ready quickly, when they may not really need to.
HR, billing, marketing, sales, etc. are just as much a part of a company as the product, and "Hire experts to do it" may not be the best advice when starting out.
