If you want to get to the heart of a terrible practice or belief, look at who is pushing it (not simply buying it) and who is benefiting. This is a very recent idea (like, you might still be able to find a grandma who was raised before that stupid shit took off) pushed to keep people poor and generally weaker than they otherwise would be. If you’ve got multiple generations, or even families, living together they have far more breathing room economically.