By doing this they're selecting for people that have a strong understanding of social interaction. That's understandable, social interaction is the fundamental

By doing this they're selecting for people that have a strong understanding of social interaction. That's understandable, social interaction is the fundamental skill of business and I wouldn't expect many startups to succeed without someone who's very, very good at it. On the other hand YC can't teach someone to hack, but it can teach advanced social/business skills (or help a strong technical team find a non-technical cofounder) so maybe they should take that into account. On the gripping hand they have plenty of applicants to choose from. Why spend resources sifting through the purely technical teams when plenty of applicants already have both sides covered? EDIT: P.S. Instacart looks awesome though, so purely for personal benefit I'm glad they got in.