If we don't install libreoffice by default we'd save around
~500MB (of
libreoffice itself and it's various java dependencies) from the live
media.
This means less strain on mirrors, and that people will get their
media faster (even if you have a really fast connection - smaller
downloads finish sooner).
At the very least it should be made possible to opt out of Libreoffice
when doing a Workstation netinstall (it is for a Gnome Desktop install).
Jens