Pulling is not as effective as having the horse bend, stretch and flex on his own (treats help a lot with this). A horse cannot collect himself without muscle, and I, for one, do not like to see the head behind the vertical. It constricts the throat and accomplishes nothing. The horse should reach for the bit, not be pulled back to it.
Just my opinions, based on 57 years of experience.
It is never the horse's fault