These coffee shop revolutionaries are comparable to "Armchair Generals" and "Armchair Politician's".
The prefixes of "Coffee Shop-" or "Armchair-" imply that the individual or individuals who desire reform or change lack the interest in making the sacrifices to take part in it. They are also the people who have the luxury of playing the all-knowing spectator to an event or social situation. An armchair general, for example, is a civilian one who believes he has all the solutions to a war which he formulated while sitting in his recliner in front of the television or while reading a newspaper.
Person 2: Definitely! Someone should do something!
Person 1: I know. Our government sucks. Too bad I'm a Coffee Shop Revolutionary and won't do anything about it.
Person 2: Me too. I'm going to get another chai tea, want one?