It is true that it is more difficult to get funds for a 501(c)(3) than a 501(c)(6). That forces the organization to operate lean and constrains possible initiatives (e.g. funding development), but also serves as a buffer against influence.
Paradoxically, a maximally independent organization may serve the interests of the long tail of potential corporate donors, because they don't have to worry that the biggest player in their space will capture it via pay-to-play.
(For those not up on the acronym, BOD stands for Board Of Directors in this context.)