She wanted more.

She wanted more for herself than just to be an underwater princess.

She wanted a life.

She needed a normal human life. 

She went to make a deal with a witch.

She wanted help to make the switch

from a mermaid to a human.

In return the witch wanted her voice.

She could not give her that.

Her voice was hers

and hers alone.

She told the witch she would give anything else.

The witch would not budge.

Ariel could not do it. 

How was she supposed to make it in the human world when she was silenced.

She knew the stories of human women and their struggles.

They had to fight and yell to become successful in that world.

If she wanted more for herself she could not let herself be silenced by anyone.