Unions are important. No individual can negotiate with a corporate monolith fairly, unions give some (but still nowhere near) balance to the equation.
Agreed, and as ATC watcher has mentioned the French ATC action is separate from wider unrest.
However the more widespread problems France is having at the moment is being driven by those leading the CGT. Their actions and motives may well be much more politically motivated and IMHO there are parallels with what happened in the early 70's in the UK...and we know what happened to unions and union membership after that.
Union influence is often a good thing but it needs to be used wisely.