Being full pay is a huge contributor to transferring. Some have high hopes (naive hopes) that if they “do well” at Bama that somehow large merit will be offered. But it doesn’t work that way. Or sometimes parents “think” that they can pay but once they actually have to pay, they find that “going away” to college is unaffordable…particularly is the parents are divorced or get divorced while kids are in college.
When I lived in Huntsville, I knew a few 'kids who applied to Bama, got accepted, and didn’t apply anywhere else. I don’t know if they thought that there was a tuition fairy out there, but come spring, they learned that they were full pay. So they started at Bama (again with naive hopes), and then had to leave once it became apparent that their families couldn’t afford “the going away experience”, and also realizing that many majors and career goals could be achieved at a local state school…and Alabama has a LOT of state schools.