I thought that wasn’t really the case as to have a chip on your shoulder implies that the grievance is mostly in your mind or exaggerated. But in terms of comics is an unfortunate reality than they are - still - looked down on, and clearly unfair. That is still there, despite the very considerable increase in their status/image over the last 30 years or so.
The phrase also implies a sense of unreasonable anger and annoyance at the perceived injustice. Of course it’s negative that comics have that lowly image, but in general I’m not angry or bitter about it. I’m so full of confidence about the beauty and intelligence of comics that my attitude is more like a mixture of mild contempt and pity for people who dont know how wonderful comics are!