I agree that realistically, it is the most PRUDENT course of action to take a QB EVERY class. With that being said, what that translates into is- at times, settling for a QB for the sake of having a player on the roster who identifies himself at that position. This can, in lean years, mean selecting a candidate from what is available, (every position has bottom of the barrel years). This, in my humble opinion, can be as bad or worse than (especially in our hampered scholarship position) using a coveted scholarship for a player that will ride the bench through 4 years of advanced chemistry for free and never even have the faith of his coaching staff to take a meaningful snap.
Conversely, If you hold out during an especially lean year, rather than suck it up and accept a "fire insurance" commitment, you can utilize that scholarship to "shore up leaking compartments" or "righting lists" in other position groups, from higher quality, more impactful players who will perform not only in class, but on the field as well.