Because they find them to be a relief.
If you send your board members out into the community connecting with important people and asking for advice, they'll usually be very happy.
It's because they don't have to do a long, detailed presentation. And they are not comfortable doing that. They don't feel that they know enough.
They ARE comfortable with the idea of seeking advice and input.
After all, they are the community representatives on the board.
It is totally appropriate for your board members to be asking other community leaders for their best thinking on how to achieve the organization’s goals.
They do not have to present a detailed case for support in order to be effective personal advocates for the cause.