How would this idea be against the spirit of open source?
> As an Open Source developer, you build a new cool library or a tool and license it under AGPL. This preserves all the Free Software freedoms for all the non-commercial users out there.
This is the part that earns my support. I see some B2B software use dual licensing arrangements that offer a proprietary commercial license alongside a source-available license that is not a free software or open source software license. While having the source available is better than not having it (since it can be publicly audited), being able to use, modify, and redistribute the software for any purpose is an essential part of FOSS. But as long as the AGPL or another FOSS license is offered as an option, the software is still free and open source.
> As an Open Source developer, you build a new cool library or a tool and license it under AGPL. This preserves all the Free Software freedoms for all the non-commercial users out there.
This is the part that earns my support. I see some B2B software use dual licensing arrangements that offer a proprietary commercial license alongside a source-available license that is not a free software or open source software license. While having the source available is better than not having it (since it can be publicly audited), being able to use, modify, and redistribute the software for any purpose is an essential part of FOSS. But as long as the AGPL or another FOSS license is offered as an option, the software is still free and open source.