Businesses exercise power and control in the market. The purpose of this is to set a precedent (perceived or actual) — the auth system was a product, not an API. Anthropic is drawing the line between 'built on us' and 'built around us.'

I don't necessarily see this as an evil action. It doesn't inhibit open source, it sets terms of service and practice boundaries.

Granted this is a wildly unpopular approach, worse has happened in the OSS world...