I know we have our Marxist definition and all that, but it seems to be a really pervasive , everywhere I go. Some people I've talked to think for instance, all scientists are silver spooned and never worked a day in their life because they don't do construction, or whatever.
How do you argue with people like this? Can you?
It has to depend on the person and where they are coming from. The concept of what is "real" labor and "real" work has no actual definition but it often comes from gendered body-destroying labor stereotypes that are perpetuated by the ruling class and its functionaries as a tool of division - and the false consciousness of the "better-thans" it normally serves.
Is this someone that works a manual labor job and feels stiffed? I'd focus on the boss or financiers being the people picking their pocket.
Is this person petty bourgeois and complaining about their clients? You probably have no chance, these people are constantly whining like victims despite underpaying their staff. You'd have to teach them political economy from scratch or find a totally different angle and hope that they eventually become conscious through a different pipeline.
Are they an unemployed college dropout looking to get a "real" career and generally expressing frustration with their life? I would redirect their ire to the fed-induced unemployment rate that they create to ensure it is always a buyer's market for labor and they don't really care what a "real job" is, just whether you are desperate enough to take what you can get.
Are they a big nerd? I would just directly correct them and say this idea is spread by big business interests ans laundered as "working class" an point them to Citations Needes.