Every college/university I've taught at allows instructors to choose their own book or has a committee of faculty members in the department choose the book. Increasingly there is a movement in state legislatures that mandate that the university system push open source textbooks. There's definitely a desire amongst a lot of faculty to use an open text book but the book has to be good and that's the hard part.

One thing to keep in mind is that publishers don't publish books to appeal to students. Their client are faculty members. So they include things like websites that handle grading online homework/quizzes. Faculty are going to use what makes their job easier. With pay not commensurate with level of education I understand why faculty have this mindset. Personally I think it's bad to use the online homework/quizzing systems out there.