Who doesn’t want to be able to crank out multiple sets of pull ups? They are arguably the one exercise that everybody wants to do, and that everybody avoids at all costs. A well-executed pull up is an impressive feat. Push ups, dips, sit ups, and many other bodyweight exercises are doable for most, but pulling your entire body up to a bar or rings is a tall order for many.
Pull ups can be thought of as the squats for the upper body. Everyone knows they need to do them, but few do them correctly. They are tough, require whole-body strength, and take a whole lot of practice to perfect.