Don, you're forgetting the other side of the coin.
How often are those that volunteer belittled, targeted for verbal abuse or run off by others? It does happen more often than many want to admit.
The wife and I left an organization we had belonged to for over a decade(in my case almost two decades), where I had held an office of some sort for almost the whole time, due to politics, jealousy and backroom deals. We both, after that, have declined to volunteer for a position in any organization and, even in boat racing, we see the wisdom in that decision.