"People should work on things which provide value to themselves, their community, and the world at large. They shouldn't be working on things that actively destroy those."
Unfortunately, lots of folks are working on things whose sole value truly is to put food on the table at home. I think there are few janitors that enjoy cleaning toilets, especially if they work for places where the workers or the public smear feces on the walls. Few folks get motivated to clean portable toilets or to work for minimum wage at a fast food place. Few folks are truly motivated to work retail.
And it doesn't matter that some of these give some small benefit to the community nor that things like fast food is a mixed thing (fast food both provides a benefit and destroys the community) or that lots of laborious jobs tend to destroy one's body - and it only takes one injury or heart attack to make one out of work.
It isn't because they lack awareness of their impact or anything, but more that folks need to survive. Not everyone can get a job with your description for a wide variety of reasons. Besides, at the end of the day society still needs folks to shower old folks in homes and to clean portable toilets, no matter how much they don't fit in your description.