Because it pays your bills...?

I.e. because of a bug in economy which makes useless or harmful jobs profitable.

It depends on how you define "important", I guess. Flipping burgers is not relatively important, useless, or harmful. It's not a "bug". It's just something that has to get done, so we pay people to do it.

Flipping burgers is useful work. Working in spam center is harmful. Web search is useful. Spying on users is not. And so on; I don’t think it’s hard to grasp.

Economy exists because it’s beneficial to society. When it results in gratifying behaviors that harm the society, I’d say it’s a bug.

> Flipping burgers is useful work.

We were talking about important work, thus my point about how you want to define important.

Screwdrivers are useful, but none of the screwdrivers I own are important. I could lose one and not notice.

I don't think it's hard to grasp.