The difference between Rome and a corporation is that a corporation can now be global.
Over 5 billion people have access to the internet. There is simply no way for all of these people to be informed. Reddit is a prime example of something taking 20 years to get where it is, having a "mass exodus" and being... barely affected (their words, not mine!)
Don't get me wrong, I am tired of it too, but the reality is that we are more people today than we ever have been historically. As a result, a mere 100,000 is both enough to keep a company alive regardless of whether the other 5 billion buy or not.
I'm not suggesting we shouldn't attempt boycotting, just that our tactics need to change for modernity. Boycotting when you and your whole town stopped buying from Joe's Wares worked. Boycotting now that Joe's Wares can make sales online means your town is never getting rid of him, regardless of whether you all never buy from him and actively dissuade others from doing so.