Only the cumulative activity of several years had any effect on u.s. policy during the Vietnam War. The November 1969 Moratorium might have had great effect, but not by itself but as the accumulative impact, brought to a point in it, of the preceding 10 years, the Freedom Rides, the Free Speech movement, the building occupations by black students, the raised fists of the athletes at the playing of the national anthem in Mexico City.
We build a movement. Does a given activity aid that task. Any argument that shifts our focus away from that is to be avoided; any action which contributes to it is to be favored.
Say a given demand is silly in the sense that if granted it would not have the desired effect. That is irrelevant. If it got people together, and if they go on, discussing and debating politics, they have made the right choice. The silly demand is forgotten & harmless.
As they said in the Civil Rights Movement, Keep your eye on the prize. And the prize is not in either helping or hurting the big banks.
Carrol