When people say they want Mabel to have character development, we don't mean that she just glitters and sweaters, we just mean that it feels and seems like she doesn't have any character flaws, which is what generally makes a character more humane.
You know, I was about to go to bed but then this came up and I just had to step in and do some educating.
Mabel is a very flawed character. It is the characterization of the fandom that dehumanizes her.
Mabel is a very selfish person. She often puts what she wants in front of the needs and feelings of others. In fact, her mind can be so one-tracked at times that she often lashes out at other characters in response to not getting what she wants.
In The Time Traveler’s Pig, she fights Dipper for Blendin’s time machine because she placed having Waddles over making her brother happy.
In Fight Fighters, we see Mabel subject Stan to his greatest fear because she wanted to be the hero. She placed her want to be someone’e helper over the actual person’s wishes.
In Not What He Seems, she betrays Dipper’s trust because she wanted Stan to be the good guy. She had more than enough proof that her Grunkle had been lying and cheating, but through out the last act of the episode she was caught in denial. And, when the fate of the world rested on her decision, she rather selfishly chose to believe Stan’s story because she did not want to believe in the alternative.
Of course, there are more episodes in which this obviously happens (more than I feel awake enough to list) but my point is this: Mabel may have good intentions at times, but she has difficulty seeing beyond her own realm. She immediately presumes that she is always in the right no matter what she does. This issue is so rampant that she is can only tackle it little by little. For example, in Love God she learns not to meddle in other people’s relationships. That aspect of her selfishness has been solved, but it’s sure to re-arise in other forms in later episodes (see: Northwest Mansion Mystery).
On top of all that, she is very aggressive. We always talk about how Dipper is willing to sit on the sidelines and let bad things happen, but Mabel will make bad things happen to other people. She kicks decorations out of spite during Gideon Rises, she wrestles Dipper whenever she’s angry at him. She’s not a passive member of the team. Once she sees a physical issue, she’s the first person to lash out.
In many ways, her combined selfishness and aggressiveness makes her very similar to Gideon. The only difference I see between the two is that she has a moral compass that he lacks. Without her compassion for others, she would be as possessive and violent as Gideon.
So the question remains: why do you, fair anon, believe that she is a character without flaws?
The answer: mischaracterization.
This is a very Dipper-centric fandom. Every work of fiction you see sprout from the fans of Gravity Falls typically utilize Mabel as Dipper’s soundboard. So many people are so intent on making Dipper the cool and dark anti-hero that they have to contrast him with an overly sweet Mabel Pines. They reduce her to match-maker or perfect angel because they are not willing to balance her optimism and compassion with her aggression and selfishness.
When I placed that twitter screen shot on the post advertising my fanfiction, I meant to draw attention to this issue. I want people to know that I understand what Alex Hirsch meant when he said that she is more than just sweaters and glitter. And, instead of absently sitting on the sidelines and nodding my head, I am shouting demands for better characterizations of Mabel. It’s unfair to the fans and Alex Hirsch to have such an excellent character be used as Dipper’s prop in every AU and fanfiction ever invented.
okay i got so excited when i saw the first picture in the preview because my mind automatically linked it with the second picture and then i remembered that he opened the door because he heard something outside (dipper and mable) and now i’m just disappointed