Here's my take.
"Fearless Girl" should be removed because it's not part of "Charging Bull" except through appropriating a portion of the sculpture not owned by the people who modified it.
Because "Fearless Girl" is not a complete work. It requires "Charging Bull" or it loses its meaning.
It also alters the meaning of "Charging Bull", in fact, nullifying it.
Appropriate? They flat out stole "Charging Bull" to be part of their "Fearless Girl" sculpture.
Theft is wrong. Even if you're sending a popular message with your thievery.