It has always been a personal pet peeve of mine when Native Americans are referred to as "Indians." It has nothing to do with respect for Native Americans or political correctness; it is entirely about actual correctness. Calling them Indians means having to actually differentiate between Indians, from the subcontinent of India, and Indians, from the Americas. It seems like laziness is the biggest factor. It is far easier to say and write/type "Indian" than "Native American." But, my History teacher and even my textbook both use the word "Indian." Is this really acceptable practice in higher education (it's my freshman year)? Is it accepted in academia in general?
As it happens, my sister is an Anthropology professor who specializes in Native Americans, particularly the Osage (and of course is part Osage herself). I'd say that counts as "academia". Here's how she put it in the forward to her last book, Colonial Entanglement:
When at all possible, it is certainly best to use specific terms, such as "Osage" or "Choctaw," but sometimes it is important to refer to larger trends affecting indigenous peoples throughout America. The term "Native American" arose as a reaction to the term "Indian," which was seen as a colonial word beginning with Columbus's confusion about landing in India. Despite this critique, I have chosen to use the word "Indian," primarily because it was the word most commonly used within the Osage community, and "Native American" has just as many of its own problems and dangerous connotations tied to things such as the environmental movement. Most frequently, I use "Indian" as part of the phrase "American Indian," to at least place the context on the proper continent. I will also occasionally use the word "indigenous," particularly when talking about the larger global population of people affected by settler colonialism.