This article addresses why instructors choose to not use inquiry-oriented instructional practices (IO-IPs) even if they believe the practices are beneficial. A national sample of undergraduate mathematics instructors (N = 269) responded to questionnaires on their use of IO-IPs, beliefs on student learning, and recognition of professional obligations--their responsibilities toward various stakeholders including the individual student, mathematics as a discipline, the institution, and society. Structural equation modeling indicates that learner-focused beliefs often predict the use of IO-IPs, but that recognition of some professional obligations can work in opposition to those beliefs. Future work advocating for instructional change could use this framework to provide instructors with resources that leverage their existing priorities.