People and their absurd theories.
EXPOSED HAIR IS DEAD PEOPLE! If you can see it, it done already growed!
Your body doesn't know that the hair was cut. Each follicle runs on a sort of internal clock that goes through a growth and shed phase. Once a hair follicle decides that it wants to go into a new Anagen phase, it sheds the hair that was initially inside and begins to grow a new one. That's why your body hair seems to stay one length. It only grows that far before it stops growing and falls out. You could shave your nutsack 3 times a day for the rest of your life and your body would never know the difference.
Except for an insanely calloused nutsack.