Well since no law allows to cancel a vote due to abstention, people should still go and vote. If you don't you are absolutly of no use for your country.
Problem with France is that for years and years (at least 30) the country is running way beyond its means, and at some points this model cannot continue to work anymore and this is what is happening with the country right now.
But the frenchs are reluctant to changes, have become too dependent to their confort and are some of the most selfish people in the world.
At some point frenchs have to realize that sacrifices need to be made for a greater good for the future of the country. But too few of them is ready to accept that.
France has to either reduce its states aids and contributions or increase taxes to fuel them, but :
Aid reduction : Half the country in the streets because "they cannot live anymore"
Tax increase : Half the country in the streets because they are taken too much money