Libre Office is great and useful but can always be installed later. That means it's a "We don't care".
But the same can be told about Evice, Eye of Gnome, File-Roller, Totem or any other "file viewer", right? But there is still some reason why we don't distribute just the "minimal installation" spin, but also the Desktop spin. It's about providing as convenient defaults as we can for our desktop users.
In this conversation I see one voice very much in favor (me), one probably in favor (Debarshi) and one neutral (Scott). I went ahead and created a bugzilla report asking for the change: https://bugzilla.redhat.com/show_bug.cgi?id=885693
Thanks.