Well, it was the principle about the 5th league also benefitting from the top four leagues moving up a place. French clubs have accomplished nothing of note to be granted three berths in the group stages given the complete dominances of the big four leagues.
But that's not what happened. What happened was that due to the Champions League winners already qualifying *for the group stage* of the UCL, Viktoria Plzen got promoted from the play off entrance spot to group stages automatically (being champions of the 11th ranked league) and PSV as champions of the 13th best league replaced them in that spot; then when the Europa league winners had also already qualified *for the group stage* (NOTE - this is a complete concidence that they were from a big 4 nation - would have been the same if, say, Club Brugge had have won it), due to the Champions/Non-Champions route, and who was already in the 3rd and play off rounds, needed to choose a non-champion to qualify (or risk having 1 unfairly balanced tie in the play offs) - and then the choices were either the 3rd best team of the 5th best league (Lyons) OR the 2nd best team from the 7th best league (Benfica).
In fact, the Europa league winners having qualified already was the unusual thing - in the past 5 finals, NONE of the prior 4 Europa league winners had even qualified for the Champs League, let alone for the group stages - and that was because of the dominance of the big 4 leagues (well, actually, Spain mainly), so they would have simply become the 5th team from their country in the Groups.
Would you have therefore complained as much if Benfica as 2nd placed team had have got the berth in the group stages, despite the Portuguese league being much inferior in results in Europe?
Or would you have preferred the winners of the 12th best league (Switzerland, so Young Boys) to be allowed into the Groups instead, despite that unbalancing the play offs and making it harder for the other league champions to get in (by this I mean, Lyons are much much better than Young Boys, so whomever would have played YB ion the "champions route" into the Groups - Dinamo Zagreb, would have had a much harder fixture, than, say, AEK Athens who play MOL Vidi) - seems that then would mean that one of the league champions getting unlucky based on the draw?
Of course, you still haven't said why you think that France have not had any success, despite all evidence to the contrary