I see the point you make regarding a contribution to society and whether it's a contribution or a job, once money/pay comes in as a factor. I think most people would say volunteers (e.g. State Emergency Service, running homeless food drives/shelters etc) are most definitely providing a contribution to society, namely because these are people who give up their free time, without remuneration, for the help of others. But if there are other people undertaking the same work (say for the same group) but it's their actual job (thus receiving an income for their efforts), I don't think that should detract from the work they do, because of the 'being paid for it' factor. As an example, if a homeless shelter had 2 paid full-time staff and 2 volunteers, their efforts all make the same contribution. Regarding your other point re: choice of career, I think it should be at least somewhat admired if someone were to steer their career based on what they hope to achieve, and hold income expectation as a lesser factor.