The answer to your question is in your comment.
When you consistently have to pick commercial software over floss because of the usability, it makes sense to skip that step and go to the commercial software right away.
It's not the role of most universities to teach a specific word processing program--or even a specific programming language, etc.
And even if someone has only used Libre Office in school, I'd say the school has done a pretty piss poor job in general if the grad can't pick up MS Word (or GSuite etc.) pretty quickly. Companies change the apps they use for specific purposes all the time and employees need to be able to adjust.