There are a few on the list for my state that I wouldn't take my half dead guinea pig to.
there are 3 hospitals in my immediate area. 2 are with the same health system and are a magnet facility. not on this list. one is a level 1 trauma center-not on the list. the other is a womens/children's facilities that is the regional referral center for ill children, has the only nicu in this part of the state (next nearest is 2 hours from here), etc etc-not on the list
the hospital from here on the list is the small one, non trauma center, that is in the nicer area of town. maybe it does have to do with what the above poster said. the poor/non insurance patients go to the not on the list hospitals generally, and like you said, probably already have concurrent issues when they come in.