The problem with this assessment is that inaction also qualifies as an action and does not somehow exempt the bystander from the moral calculus. If you disagree you'd also have a difficult time arguing that people who don't participate in forms of other activism should as the retort could simply be they're just a bystander and that there's vanishingly little untouched by the Capitalist system so they just won't do anything proactive.
Unless you literally live in the woods and grow your own food, you're likely interacting with a mini Capitalist trolley problem every time you buy food or turn on a light switch. Being asked to stop another few genocides and not make the current one worse is just one more.