I agree with not wanting to being paid. It sets standards (sometimes unrealistic) and creates a strange work environment (im referring to Graal, as normal jobs are much different).
That being said though, the "higher ups" should acknowledge the volunteer work that is being done and take steps to improve the game. For example, lag has always been an issue for Graal, yet Unixmad hasn't done much of anything to fix that issue. It would help for him to be communicative in the community, but I don't see that happening either.
So in ways I agree that the volunteer work is exploitative, only because the higher ups aren't even relevant in the game, just the team of volunteers are. And even then, they have little to no contact to the higher ups too.