Pseudoscientists use fantasy art to depict black holes because none have ever been observed (observation is a requirement of the scientific method).
Stephen Smith: BlackMax and Black Arts.
Black holes are undetectable by any instrument, so a computer simulation has been created for the Large Hadron Collider to act as a substitute for observations. ...
Most children are taught in elementary school that dividing by zero is not proper numerical manipulation.
Instead, a flight into the mathematical fantasy of General Relativity was required, where master calculators allowed black holes to become the reified monstrosities that so enamor modern cosmologists and astrophysicists. Cosmologists use the singularity product to describe conditions that existed before the Big Bang, while astrophysicists use it to overcome almost any problem that appears in galaxy studies.
Galaxies spin too fast for a certain theory? There must be a black hole hiding somewhere inside, providing additional, unseen gravitational power. Galaxies emit tremendous quantities of light energy or cosmic rays? There has to be a black hole inside the core, sending out light-years long jets because matter is being compressed and superheated before it falls down into infinite darkness. What else could it be?