First off Evan, as I'm sure you appreciate, this isn't your only chance, your only 10 minutes. It may be your only 10 minutes with YC, but you've still got a lifetime (or 3 years, whichever comes first) of 10 minutes(es) in your business.

It seems to me you focus lots on the 10 minutes issue, and yet you understand why the limitation stands. What you may be missing when you refer to PG&co. not knowing the nuances of every business, is that they shouldn't need to know the nuances of every business in order to make a go/no-go decision.

Could it be your focus on the nuances rather than the big picture may have been a self-imposed limitation?

I don't know what industry you are involved in, or anything about it, but the simpler you can make something seem, the more approachable it becomes. If you are getting into nuances that can't be understood without background knowledge, it could have just been to complicated when other interviewers had a clearer message.