France, World Cup winners in 1998 and runners-up in 2006, were among the nine teams in the second tier and will also face Belarus, Georgia and Finland after being drawn in Group I.
"I don't know why France are in the second group, why Greece, Norway and Croatia are ranked higher," Blanc told reporters after the gala draw held at a yachting marina near the centre of Rio.
"We had to face one of the top [seeded] teams, and we got the biggest," he added.
"We should have been in the first group - and now we have drawn the best team of the last World Cup, but then, you have no choice."
FIFA based their seeding on the world rankings and France's 10th place among the European teams put them in the second tier.
With only the group winners assured of an automatic place in the finals, one of Spain or France will most likely have to qualify through a two-leg European play-offs to reach Brazil.
"The qualifiers are always dangerous... Belarus took four points," Blanc said of the eastern European team who are also in France's qualifying group for Euro 2012 and upset them 1-0 in Paris in September before a 1-1 draw in Minsk last month.
However, Blanc tried to focus on the positive side of being in the only one of the nine European groups to have five rather than six teams.
"If you only focus on Spain, you'd say 'it's impossible, it's a very difficult group' but the first team qualifies and so do the best second-placed teams.
"It's not a disadvantage to be second... logic would say we'd take [second] among the five teams," he said.
"It's two matches less. In the calendar that can have it's importance," he added, referring to physical toll on players at the top of the European and international game.
"The best international players play in the best clubs so they also play in European competitions."
He also relished the prospect of facing old rivals Spain.
"It will be a beautiful match because... to face the best is always enriching."
His opposite number Vicente del Bosque did not attend the draw.
