And there's absolutely nothing wrong with people looking after themselves. A lot of of the people committed to a mission are going to end up getting screwed. (Not everyone, but probably most.)
Even if there are some very rare individuals that go to work primarily for companionship or for personal fulfillment that doesn't mean it's even worth bringing up in a discussion like this
It's obvious that few people are going to subordinate themselves in a world where they don't get paid for doing so, and if they did it would look more like volunteer associations (only emergency response involves much hierarchy, most volunteers are only loosely associated with the org, individuals choose which shifts to turn up to, local leaders are elected and view it as a burden rather than a privilege) and less like work (you don't get to choose anything).
Edit: I should add that I'm in no way against jobs, I just think that people who are doing largely unproductive work for free are still working, even though it'd be better for everyone if they were getting paid to do something more useful.