Aren't "interviewing skills" essential to founders? Isn't a YC interview basically a chance to pitch your company and answer probing questions about your plan? Seems like a pretty fair qualification to me...
All of these are 'soft skill' competencies that hackers tend to downplay. But you need someone who can do this and do it well.
In other words, you by failing to distinguish scaling phenomena (1->N) with a gating criteria (0,1), you are making an attribution error concerning the "essentialness" of your explanatory variable.
For example: co-founders are typically not "interviewed" for the job. But (a) their selection is essential; and (b) if you can find a co-founder, you can find any lesser employee.
It could be argued, that having the ability to "recruit" without formal interview is actually a more essential skill.