How is that any different from a major open source maintainer deciding to quit the project and leave it out of date? It’s an identical outcome for the end user

How is that any different from a major open source maintainer deciding to quit the project and leave it out of date? It’s an identical outcome for the end user of the OSS. You wouldn’t demand that someone continues development of the project for free right? So they can either leave the project to rot, which seems morally fine to everyone, or they just also decided to start charging money for future updates.