At many institutions, there are barriers and risks associated with changing one's teaching. Institutional structures may de-value teaching and teaching innovations. A clear message is sent by the institution if research excellence is recognized and rewarded while teaching excellence is not.
Institutions can be unclear about their teaching expectations.
Teaching excellence is always expected and often stated in the institution's mission statement but what this means may not be articulated. This may leave an instructor uncertain and convince them that the traditional approach satisfies teaching excellence since it is found throughout the institution. Even when an institution creates an environment that encourages and embraces teaching innovation, instructors may encounter resistance. Instructors accept the traditional teaching style often because they were taught this way, their friends teach this way, and they're comfortable with this style. Instructors may feel they teach well and their students learn, so why change.