It is to some extent, because they exist in the shadow of NDSU (and did even when both were D2 schools), and to some extent, Concordia, which has the kind of private school/alumni interest not generally found the in MnSCU public colleges.
Both schools have seen enrollments drop 40% or so from their peak but SCSU was so much larger, that I think it's hurt them a lot more. MSUM was actually over-enrolled at the time I attended and was actually for a couple years, larger than NDSU in terms of enrollment. The current size of around 5000 students seems about right for the campus.