The 44% graduation is for all majors, not the nursing school.
UNM accepts any instate applicant who graduates from high school with a GPA of 2.5 or better and the state pays 85% of their tuition & fees to attend college. (100% for Pell eligible applicants.) A lot of under qualified students enroll–and then drop out because they cannot hack college level work.
UNM also attracts a lot of adult students who are working their way through college. They drop in and drop out frequently.
Both of these item contribute to UNM’s low graduation rate.
Students who are academically able and motivated will graduate on time and find plenty of opportunities at UNM.