I remember when, several years ago, Mechatotoro and I started to use Libre Office and moved to .odt for all our word processing needs. Some colleagues did try to force Microsoft file formats on us in spite of the university's approval of ODF.
But slowly, more people have come to understand that open source is here to stay and that closed source is neither better nor safer. At the end, most of the complaints by closed-source defenders can be reduced to the following:
1- They are used to X and don't want to learn anything new.
2- They want to use open source but are locked into closed source.
3- They think closed source is better because X has more features. [Which, by the way, most people don't know about or don't really care for because they don't use such features and probably never will.]
4- They had a negative past experience with open source and did not care to update their knowledge.
5- They don't really know what they are talking about but pretend they do.
6- They simply prefer closed source as a personal choice.
In spite of all that, I've noticed that more students know about ODF and some of them are using Libre Office themselves nowadays.
An interesting case happened a few days ago: a student who wants me to direct her thesis is interested in using Twine, an open source tool for writing interactive texts.
The world is changing. Many just don't really see how it is doing it.