Nonprofit boards are willing to lower their standards (for outcomes and exec performance) because:

They don't really own their nonprofit

They don't get any tangible returns (like compensation for their time, expertise and connections)

They don't always understand the details

They only spend about 25-35 hours a year with this particular demand

They often have lots of competing demands outside of this one demand

The result: they accept lower standards than they would if none of these conditions true.