WHY? Because the Boogeyman preys on fear, resistance, disobedience, and discord. That is its power. Symbolically, the more one complies to the system, the less likely the boogeyman materializes—and that is why the monster lives. It is apart of the system to keep people in a constant state of fear from being original, unique, and creative.
References:
Bogeyman | Origin, Definition, & Synonyms | Britannica
Bogeyman (Boogeyman or Boogie Man): Mythical Monster | Mythology.net
Bogeyman: Mythical Creature – Mythical Encyclopedia
* All images are not mine; therefore, I cannot take credit.
-RADolence