No one is extending anything. It's a term in economics and in public choice theory. The short definition is "seeking to increase one's share of existing wealth

No one is extending anything. It's a term in economics and in public choice theory. The short definition is "seeking to increase one's share of existing wealth without creating new wealth." In this context, "creating new wealth" has a specific definition as well. Sitting on a SaaS service, or charging license fees for software I wrote a decade ago isn't it. Building a house and getting paid for clearly is. Rent-seeking is usually bas, but it isn't always bad. Creating wealthy early on in your life, and then sitting on passive wealth generation feels okay to me. However, if you have a legacy family where wealth was last created 500 years ago, and everyone is extracting wealth by virtue of having been born into the right family, that's not okay. Your values may differ. That's okay too. Values differ between individuals and cultures.