It might shock you, but there are many Quinn fans that actually like her like she is and don't want to fundamentally change her. DPC seems to not care that much about that portion and assumes everyone is on the 'I can fix her' train.
I wouldn't say it's primarily about "fixing" her.
It's character growth. I love seeing it. I wouldn't expect a college student to be completely stuck in their ways.
Their character and world view are still growing.
She has clearly experienced trauma in her life and has trust issues. It's nice seeing her break out of that mold.
I don't believe her being "fixed" fundamentally changes her either. She shows glimpses of vulnerability with her interactions and how she glances at the MC. She has worn a cold-blooded mask for so long, that she has become it.
Still, it's just a mask created by trauma and self-preservation, and the MC is helping to peel back the layers.
I enjoy this direction. Kudos to DPC.
A character that doesn't fundamentally change is someone like Becky. She is a vain real baddie. Big ego and competitive.
She attempts to wear a pleasant mask to conceal her inner darkness. But she's so fake that her attempts are transparent.
Becky has shown no inclination to changing thus far.
Quinn is not like Becky. There is warmth underneath the cold mask and potential for positive change.