How?
You're equating the concept of monetary value with general value. That those two things are inherently the same is a core belief of liberal/bourgeois ideology and IMHO: false.
A guest invited to a home for food does not believe that food is inherently free.
What if the food was scavenged?
What is a guest in reference to a society?
Let's say a traveler who is not from here and isn't part of the society I live in.