> In particular, I've always wondered why "GPL or ask me for permission" isn't being explored more.
Because handling “ask me for permission” is expensive, even if you say no, and you can only do it if you sacrificing much of the main benefit to using open licensing, which getting free work from downstream, since people having to give code ownership to you makes them less likely to contribute back anything that you can use with your licensing model, even if they are doing GPL derivatives that the rest of the world can use without the “or ask me” part.
Do you posit that people are more inclined to share contributions to a codebase that does not ask them to share such contributions?
Or do you posit that GPL (or another reciprocal license) prevents adoption of software where a MIT (or another permissive license) would lead to adoption of that same software?
> Do you posit that people are more inclined to share contributions to a codebase that does not ask them to share such contributions?
I posit that people businesses share contributions because it brings them business value, and the business itself being able to use the code in proprietary derivatives often significantly enhances the business value from sharing contributions, which is why SQLite (available as public domain or permissive license) and PostgreSQL (permissive license) have significant upstream contributions from downstream proprietary users, and even Linux gets a fair amount from people whose main use motivating modifications is hosted use which does not require contributions (because it's GPL, not AGPL.)
I further posit that, OTOH, people who don't want to control downstream use are more likely to contribute if they can do so with a license that doesn't constrain downstream use.
But most critically I observe that a GPL-or-proprietary offer cannot use GPL-only contributions, it requires acquiring rights from downstream contributors to relicense code under a proprietary license. So even if people are contributing under the GPL, that isn't “giving back” to the vendor of software that is under a GPL-or-proprietary license scheme (where the value proposition is that the proprietary offers at least as much in all dimensions as the GPL version, and more in some), since by adopting that license scheme they have locked themselves out of use of community improvements that are offered only under the reciprocal provisions of the GPL, which can result in the proprietary version being supported by less aggregate development resources than a community, GPL-only fork.
> ... even Linux gets a fair amount from people whose main use motivating modifications is hosted use which does not require contributions (because it's GPL, not AGPL.)
I'm not aware of any Linux mods not being shared upstream (or at least intended to be eventually PRed to master), except maybe grsec? Please don't give them (AWS/Azure/Google) ideas; we might soon see eg. proprietary drivers for datacenter hardware or Docker/k8s-specific kernel mods. That's a case AGPL could've prevented (though again, I don't know of any proprietary kernel mods).
Hm, come to think of it, the possibility of security-piercing the kernel, then to offer the result as a Linux VM or worse, for hosting Docker-like containers, is concerning. One reason more to buy real VMs with a verifiable standard distro installed, rather than "containers" I guess.
> I'm not aware of any Linux mods not being shared upstream (or at least intended to be eventually PRed to master), except maybe grsec?
That's my point: they usually upstream changes even when they don't legally need to, because they benefit from the changes being upstream and not something they have to maintain in separately.
I would suggest that a project run by an foundation whose entire purpose is Free Software and which strongly prefers making its own software available under exclusive reciprocal license for ideological reasons tied to it's central purpose has a very different position with regard to securing contributions of code ownership from people interested in contributing to the community than a company licensing software under a GPL+proprietary scheme, whose implicit ideology is “we should get paid by commercial users for what we develop, but you should not for what you develop for us”.
Because handling “ask me for permission” is expensive, even if you say no, and you can only do it if you sacrificing much of the main benefit to using open licensing, which getting free work from downstream, since people having to give code ownership to you makes them less likely to contribute back anything that you can use with your licensing model, even if they are doing GPL derivatives that the rest of the world can use without the “or ask me” part.