I've not heard that term used, and its bad. You shouldn't dehumanize people for being "cheap labor". Honestly, that guy flipping burgers is doing more real good for people than any number of highly paid software devs working on VC funded projects that will mostly end up in the trash.

I think it's more acceptable to make fun of people of your level of privilege and up (like the management who underpays) and less of those lower.

If a fast food worker at a better paying, better run chain or restaurant said it, it would be still a little mean (as intended), but not kicking down.

yup. They call it punching up. No one likes someone who punches down. lol