It's even more specious than you think. Red Hat employees are the largest "contributors" to GNOME. It's effectively a Red Hat project.
So, Red Hat project GNOME relies on Red Hat project systemd, and Red Hat employees won't allow systemd to be portable to competing platforms. Convenient.
So, Red Hat project GNOME relies on Red Hat project systemd, and Red Hat employees won't allow systemd to be portable to competing platforms. Convenient.