Why did Pango switch to using GraphicsMagick instead of the more popular ImageMagick in the pango-view tool?

https://gitlab.gnome.org/GNOME/pango/-/merge_requests/472

No explanation and the first comment from a developer, "I can't say I've ever heard of a 'gm' command". Me neither. I just reverted this in /etc/portage/patches on my Gentoo system.