Likely based on their own limited personal experience.
While I agree that having solid nursing experience during NP school is useful, the closer I get to graduation (3 months away), the more I realize that it probably isn't as important down the road. To start, my CVICU/ICU experience has been huge in helping me understand patho, various medications, and with independent thinking, all critically important to any learning NP student. Additionally, it was really useful in helping me find preceptors because I knew such a wide array of physicians across numerous disciplines.
That said, down the road a few years from now, I imagine the differences between myself and classmates that had much less experience going into the program is going to be minimal, and largely based on the work experiences obtained after graduation. I think of it somewhat similar to classmates during undergrad that were seasoned CNA's or MA's during our program, with tons of bedside experience, to individuals like myself that had never stepped in a hospital before the first day of clinicals. During school they had a very large upper hand, but a few years out of school, there probably wasn't a single difference.
Overall, the role of any APRN isn't for everyone, and it takes desire and strong constitution to will yourself back to school and completely start anew. Too many people here are focused soley on salary in all aspects, which don't get me wrong, is important. However, that are several other things such as quality of life and personal satisfaction that comes with being an APRN.