He could pay people for their work

From the AGPLv3:

> This License explicitly affirms your unlimited permission to run the unmodified Program.

> If you modify the Program, your modified version must prominently offer all users interacting with it remotely through a computer network (if your version supports such interaction) an opportunity to receive the Corresponding Source of your version by providing access to the Corresponding Source from a network server at no charge.

As long as you don't modify the source the AGPL absolutely lets you "take the work and not return anything". Even if you modify the source the only thing you have to provide is the modified source code, and not even to the original authors -- to "all users interacting" with the your service.