@Vincentt Alright, forget the simile.
If no sitting party address one or several issues, but actually support and enforce the reason behind the grievances of their voters, they fail their trust. This is what gives rise to a protest party. When/if the sitting parties agree to take these issues into consideration and change their politics the protest party has no purpose anymore. If they don’t, the protest party will develop it’s politics and in the end it will either lose support or be a full fledged party.
Simply said, there is no better way to protest when the establishment fails. The french seems to do it differently. They crash windows, burn cars and block the freeways.
If voter grievance in some of important questions is bigger than they value many of the rest of the range of politics, there is a good reason to vote for them.
It is the same with a feminist party, or an immigration based party.
The reason for the rise of this party is because people have no other party that address their integrity and privacy in telecommunications and internet. This is a national and european issue. I am sure you too watch what happens in France right now, and the Telecom package in the Union. Many countries in the Union deals with these issues, and the parties of my country has failed to pick this up. Thus, the support for these democratic core values.
Many see it as it is not of much importance of how social issues are addressed if key democratic freedom is taken away from us, because we vote for a party that address social issues, but is responsible for the invasion of citizen integrity, changing laws to invade privacy.