I think it's becoming more clear that intelligence alone is not enough.
I'm also very worried that 10 years from now we'll have an even bigger problem than Daesh in the Middle East, even if Daesh is "wiped out" - Al Qaeda was wiped out, too, unless we forget. Daesh is much bigger than Al Qaeda was, which means they have many more relatives and children than Al Qaeda had - children that may rise up again in 10 years to avenge their fallen fathers and cousins.
France's reaction feels very much knee-jerk and 20th century thinkining - "Someone attacked us? Let's bomb the hell out of them then!". It kind of reminds me of when the French generals ordered their foot troops into the Germans' machine guns a century ago, because that was their 19th century thinking at the time.
This is a whole other discussion that also needs to happen, and I think a much bigger issue than the encryption one.
Conversely, if there is too much data and everything is hidden because there is too much, then why bother with the clamor for encryption? I mean, there is so much data, it's unfindable?
I think it was Poland and Russia sending cavalry and barely armed infantry into modern battle, not France during WWII.
It's not to make it 100% foolproof, it's to make it so that any misstep would reveal them. In other words, make the whole of their communications system leaky _somewhere_ not necessarily everywhere.