Your own comment that you've linked here, which mentions Russ Allbery, has him quoted saying, "Most of those [systemd] components are clearly superior to anything we have available now on Linux platforms and will be used in the distribution going forward".

Then there's Fedora, which is upstream of Red Hat, who has many of it's contributors as Red Hat employees, so I don't see how it's odd that they would adopt software that Red Hat are invested in.