I've been thinking about this a lot lately. Many jobs seem to have a net negative value for society - soda, highly processed food, credit cards, car dealerships, (most) sales people, etc. We'd probably be better of as a society paying these people to do nothing than to do what they do now; we'd be even better off if we paid them to do something actually productive. There might not be a perfect solution for this problem, but we don't seem interested in having a discussion about any solution to it.
Like you said, we have a curious moral framework at play here. For instance, a highly paid person who has a job with a net negative impact on society is often considered more moral than a beggar on the street (and it should be noted that the former is going to be consuming more resources from society as well). Because most people will calculate someone's worth by having a job, not by judging its impact on society (at least, most of the time).