I think the causation goes the other way - at least to a certain extent. If you look at the chart showing DSA occupation breakdown, you can sum up teacher, nonprofit, public sector, social work, arts, political organization, and student, and it comes out to 46% of their membership (if I’m doing my math correctly). In my view, this is not the story of, say, the accounting student who was promised a good paying job after college and then got shafted. Instead, it is the story of students who intentionally chose lower earning career paths for the sake of doing something “meaningful”.

Which follows from other things Silver said in the article - that the main talking points of the DSA/American left are social, rather than economic. The modal DSA member may nominally be a low earner, but they actually occupy a higher socioeconomic class than their wages indicate - hence, they can spend a lot of time worrying about Palestine instead of worrying about how to put food on the table. They have a realistic expectation that if they run into financial difficulties, that their social network of friends and family will be able to bail them out.