Should Bitcoin ever achieve the kind of ubiquity its most ardent fans hope for, these people will wield more financial power than any of the Banksters they decry.
This is true, and the most practical reason Bitcoin may be superseded by a crypto currency that has an adoption curve similar to this.

They will also control such a large amount of the monetary base that they too could end up becoming plutocrats
Far from being a revolution, the future as envisaged by Bitcoin fanboys will be little more than a changing of the cast of villains.
This is unlikely in the long run, in contrast to gold it is not as practical to plundered through physical force and war and alternatives can emerge.
Moreover the people who partake will partake voluntarily and will be able to erode the top down wealth by saving, an attribute that has been removed from the inflation fiat central bank model.