He didn't cheerfully refuse to fix it:
Well, cgroups-less kernels are explicitly not supported by systemd. However we added some hacks to allow it to boot to a certain degree even if a lot of things will not work correctly afterwards. In this mode when you boot you will actually get a warning on screen and bootup is delayed by 10s to make sure the user understands this.
Now, this mode recently broke, and it will segfault early on. I am happy to take a patch to 'fix' this again, but I will not work on this as i dont run kernels like this, and as mentioned its not really supported anyway...
Another option is to simply be honest amd stop supporting in entirely, and refuse booting completely. And I figure this is what I will eventually do if nobody cares enough to send me a patch to fix that segfault.
He's happy to accept a fix the segfault. He will take a patch or just have systemd refuse to boot. You were misrepresenting his position by saying he refused to fix the segfault.