In all of my Amtrak travel, including in Sleepers and Club cars, I have never witnessed groups of non-travelers gathered near the trains. Maybe Salinas is an exception, but I travel often through the Bronx, including some rather rough sections, and I have never seen gatherings. Likewise in the bombed-out parts of Philadelphia.

I think if there are gatherings expressing class anger, there are more obvious targets at hand then the LD (or regional) trains.