How important is for YC founders to be ethical in a world that cares mostly about financial success, profit margins, exponential growth, etc? Think Theranos, Zenefits et al.
I don't think that's a fair assessment (I'm not affiliated with YC in any way). I think that:
> Not using misleading, illegal or dishonest sales tactics.
> Keeping your word...
and:
> Generally behaving in a professional and upstanding way.
cover more ground than you imply. While it might not hurt for them to take a few more stands (e.g., "ensure the integrity of customer data", "don't be a net drain on public resources"), I think it would be a bit difficult to add a lot more ethical requirements without getting overly industry-specific and excessively lengthy.