Financial services account for a substantial portion of the US GDP and some may argue has big sway in the way our laws are written, and now in steering conversation about them on a popular site.
I think that's a big assumption. Financial services firms are not usually savvy marketers and the big wall street firms everyone hates almost never try to appeal directly to consumers and would have little to gain from swaying opinion on reddit. I'd wager retail firms are far more active on social media.