I, too, am bothered by the idea of "cut once, cut always". Suppose a PNM had been cut for poor grades, but she's managed to bring them up, or a great PNM had to be cut because of release figures... it bothers me that she will never get a second look.
However, it is up to each GLO and each chapter to set its own guidelines for membership selection. I may not agree with the "cut once, cut always" policy, but that's what the chapters at LSU have chosen to do.
LSUgrrl, chin up, and good luck with whatever you decide.