It's true that this system is completely unfair. It was the same when there were 24 teams at the World Cup. Still, in reality the 2nd placed team in group E gets a very easy draw to the Semi-Finals, while the 1st and the 3rd teams get a difficult one.
So group A is the best one. Did France get drawn there or automatically placed there because they are hosts? If it's the second, then kudos to Platini for arranging the easiest possible way to the Semi Final for France.