I am afraid that "radical" or "revolutionary" are too often code words for hooliganism. With that in mind, the distinction should be between those committed to institutional changes and those interested mainly in creating ruckus and ass kicking. The former has greater appeal to people identifying themselves as liberals, the latter - to the folk described by Joe Bageant, especially frustrated males.
I am not against creating ruckus if it serves creating progressive institutional changes - but it is rarely used in such a way. More often, it is a way of venting personal frustrations or worse yet, it is 'astro-turf' - a strategy pursued by the powers that be to foment popular anger and direct it at the enemies of the established order. For example: pogroms in Eastern Europe, lynching in the US, "Cultural Revolution" in China, Islamism and Wahabiism, and right wing populism spun off by the Republican Party.
Wojtek