[Tichy]

I think it is a little bit more than that: the feeling is that the established parties are completely detached from the problems of normal people, and certainly don't represent their interests anymore. One comparatively harmless recent example: one politician got caught for cheating on her PhD (copying stuff). So she lost her job in parliament, but next she was offered a job as "science relations adviser" for the European parliament (especially her who had just betrayed the institutions of science) - a slap in the face of the honest population.

The pirate party promised to represent the real people, it is written in their genes that they want to prevent politicians being politicians just for the sake of power. For example the discussions sometimes go so far that they think their representatives in parliament should only act like puppets executing the decisions made by online votes.

Whether they'll manage to deliver is another question, but they don't claim to have all the answers and their intentions are pure.

The thing is, that lack of answers is often held against them. But if you think about it, the other parties don't have the answers either. They just stumble through blunder upon blunder (for example dealing with the financial crisis). It's just a human fallacy to assume somebody who takes a firm stance is also competent (this was even shown in psychological experiments).