The premise seems wrong. I thought the current thinking that building a group you as the "social accountability" of your goals just produces anxiety and procrastination.
And I don't see offline sync as a "nice to have." I (and others) have dropped products when they dropped the feature.
Does that really matter so much? I've never heard of South Bay startups agonizing that they were in Sunnyvale instead of Palo Alto, and the distances involved would be quite a bit larger.
Obviously design was a high priority, as they said, even inter-office documents had a high standard.
I think when you have a designer leading the team, design becomes the most important thing. When you have a programmer leading the team, the code becomes the most important thing. When you have a business person leading the team, it's the metrics, etc, etc. in reality the customer is the most important thing.
At the time my friend brushed off my comments and it looks like this post-mortem doesn't cover half of what it needs to. The premise of the app completely missed the mark for the problem it was attempting to solve.