I definitely agree that "a preoccupation with subculture is often an indication of a political movement's marginality." That is very, very well out and something that the Left, especially with the art and design of pamphlets, clothing, music, etc. has a serious issue with.

I once volunteered at an "anarchist bookstore" (whatever that means) where the vibe was 500% cooler than reading books or actually doing anything. This is an issue that the Left suffers from, and although we might point our fingers at centrist candidates, they have found a formula that doesn't alienate people. Like the right, the Left must be careful in its own extremism. Just because it claims some sense of moral superiority doesn't translate to making real world change. The internet and social media don't make this any easier.

Pan also hosts a talk show on Jacobin's Youtube channel where she discussed this further. Here is the episode: https://inquiringreader.org/texts/2021-01-21-the-jacobin-show/