As a founder perhaps, but they have more relationships and reputation to manage than just with founders. It appears as though Andreesen was considered a truste

As a founder perhaps, but they have more relationships and reputation to manage than just with founders. It appears as though Andreesen was considered a trusted board member enabled to negotiate in the shareholder's interests, and as you say he was founder friendly instead. Probably a one time thing they don't have to worry about too much. But do that a couple of times, and they might start to have problems finding co-investors on bigger deals if the perception is that the investors won't hang together as a class.