I think you’re partly right but it’s not the whole story. People (not all but many) notoriously treat service/public facing workers horribly. The same people also treat those workers’ supervisors with more respect, or at least with less aggressive behavior.

They’re paying for whatever product or service they went in for. It’s not because something is free, it’s because they’ve designated certain people as servants.

I think there’s a pernicious attitude that the “free” part of open source is an entitlement to service, and that the people providing it are servants.