If you focus solely on the publishers, your impact will be minimal; they can ignore you. But publishers get all their money from institutions. So you could focu

If you focus solely on the publishers, your impact will be minimal; they can ignore you. But publishers get all their money from institutions. So you could focus your energy on forcing institutions to stop using the publishers. But you will find that institutions don't want the model to change. They want to pay less money for publishing, but they don't actually want to lose the paid journals, because their whole research funding model would collapse, as it's built entirely around the reputation of the journal. Either institutions have to completely re-invent how they fund and organize research, or someone has to get paid to do the actual work of maintaining journals. The publishers' profit margins are one thing; anyone could start a competing publisher tomorrow and take a fraction of the profit. But people are not asking for reduced profit, they're asking for abolishment of paid publishing, which is like saying, let's abolish the entire system of scientific research.