Why consider alternatives when MS basically gives away their software for almost free to these institutions? The point is that MS depends on these sectors and gives them licenses for practically nothing because at the end of the day those users who are used to those platforms are going to be most comfortable with them. You used MS office in school or in work? Now you want to use it at home for all your stuff, any alternative will just not feel as comfortable, or you will be too brain dead to know that alternatives exist out there.That's part of the problem really, microsoft and google have the productivity apps in schools closed to a monopoly with office 365 or google drive respectively, so if you want to use something else you might be out of luck.
Honestly I wish more School boards would consider alternatives but it is what it is.
That is how that works, Apple did the same thing back in the day with Computers. Its a form of indoctrination, or a drug. You hook them in when they are young and they become paying customers for life.