I agree with that too. I joined the Labour Party when I was a teenager, and quickly became part of one of it's more radical factions.
One of our maxims was "Educate, agitate and organise". Our aim was to attempt to harness the discontent and channel it into some kind of effective activism. That, in my opinion, is the task of all radical organisations, whether official political groups or grassroots single issue campaigns like Plane Stupid.
A few scant years after young people had been torching cars in a run-down suburb of Liverpool, they were joining and working for political organisations that eventually got radical politicians into public office. The Labour Party's response? They expelled the radical politicians in their headlong rush to court the middle class vote.
But the anger didn't go away. Who should we vote for to bring about peaceful change? If that question has no answer, I can understand why people turn to other means.