@Strop:
Hey, the ability to take the other side of an argument to explore the corner cases of your own argument is a rare thing. My hat's off to you.
Is there a way to actually justify this premise on any other basis apart from the economic 'growth is good'?
The effect of an extra person in a community is multiplicative, not additive. For instance, with only 2 hunters in a group, maybe the largest animal they can hunt is deer. But with two more hunters, they can drive a whole herd of deer off a cliff, and get much more than just twice as many deer for the village back home. Now, there is a point of decreasing returns, but once you have a large enough population that not everyone has to go out and hunt, one or two guys can stay back to fix the spears, or make new bows, or come up with better ways to find food (like agriculture). Now the society as a whole doesn't want for food, in a way that wouldn't be possible with fewer people, and society can progress.
Of course, the economic "growth is good" argument is fairly sound also.
Simply speaking, it's because it feels rewarding to have somebody working as part of a productive fellowship.
Of course, there are non-material benefits to having more productive members of a community, they are just harder to quantify. Of course more friends that you have, the better you will feel, and there's plenty of management material out there that notes that a happy workforce is more productive.
The value judgment that bums hurt a community seems intuitive to me: Most people would rather live in a city where everyone has a job, as opposed to a city where there's a guy on every street corner. City governments constantly pass laws against loitering, soliciting, and panhandling, so it seems that there's some people that don't think having people live off the scraps of society is a good idea. It's definitely an area ripe for exploration though.
What other 'outside of the community' justifications did you have? I'm interested to know.
A Kantian view of individual happiness over time. If we (somewhat arbitrarily) say that a good day for someone gives +1 to their happiness, and a bad day gives -1 to their happiness, then allowing someone to kill themselves after a streak of 30 bad days isn't sound; they can recover and have 100 good days later if they hadn't committed suicide. If people who commit suicide tried to solve their problem instead of escaping it, they would have a more fulfilling and happy life for themselves, instead of ending on a rather down note.