You put your finger on the glaring weakness of Pelz: He treats golf, which is supposed to be a game, as though it was rocket science. Anyone who plays less than three or four times per week is going to find it almost impossible to ever assimilate all of the technical, mechanical aspects of Pelz's tomes.
Utley teaches basic mechanics, and then tries to enable you to allow feel to govern your shots. The fact that your buddy was incapable of properly applying the inside-square-inside stroke is not an indictment of the method as a whole.
The vast majority of recreational golfers will never have the time required to learn and master Pelz's system. It's simply too involved, too mechanical, and too hard to retain unless you are playing and practicing a LOT. Utley has simple, easy to learn, easy to retain methods for the short game that will be a huge help to most weekend players, IMHO. My short game is much better since I read Utley's books. My worst short-game shots today are better than my average was before, and I'll happily recommend Utley to any who will listen. If you're a feel player, read Utley. If you're a technician who wants to have labels on the shafts of your wedges telling you the four yardages with that club depending on which of four swings you employ for that shot, and pictures from four angles of every conceivable variety of bunker lie, read Pelz. No one can cite Pelz for not being thorough enough.