I don't get your distinction between proprietary and OSS. It wouldn't be proprietary if this were an established license. Proprietary to me means you're bound to a vendor - here you'd just have to chip in for development if you're selling derivative works. (and you can and are encouraged to do that)

AGPL doesn't have any mention of commercialization - you can use it as an end user in any context for free, but you will have the same issues with selling derivative works due to copyleft. For software that's actually just software and not a service, say media production, it means that *GPL software will forever remain tools for hobbyists.