once people start doing this, the companies will change. The companies will start valuing the customers more.
Even a vocal minority can have a profound impact on things. Look at how people got mobilized to let their representatives know they didn't like the ACA repeal bill which did end up having an effect on congressional members. Or more recently, how groups mobilized and pushed an ad boycott of Bill O'Reilly. There's even companies who opted to drop Ivanka Trump's line of fashion because of public outcry.