I don't mind adding forks to the list, or distros based on other distros, as long as the distro they're based on is a community distro and not a corporate distro. Like you point out though, there aren't a lot of those.
The issue isn't if something is a fork or not, the issue is if something is a fork of a corporate distro. For instance, there are forks of Arch that still meet the criteria because Arch is a base community distro, whereas OpenSuse is a fork of a corporate distro.
But how many of those meet the criteria of not being based on corporate distros and are also user friendly? For instance, I wouldn't exactly classify Gentoo as user friendly.
I don't mind adding forks to the list, or distros based on other distros, as long as the distro they're based on is a community distro and not a corporate distro. Like you point out though, there aren't a lot of those.