That should teach you not to listen to Phil and Paul...
A rider like Voeckler, with his morphology, isn't going to respond well to the chirpy attacks of the lighter climbers. Just look back on the threads from yesterday. Several comments on Voeckler being in the big ring at one point as he followed Basso through one of the switch-backs.
Voeckler is a grinder. That's what makes him excellent as a rolleur in the breaks. On longer, more sustained (and consistent) climbs, he can use that to his advantage. Repeated short attacks are what will be his downfall. At some point, gradient certainly comes into play, but to some extent grinding is grinding, whether it's into a headwind on the Massif Central or a sustained climb in the Alps. It's when the grade really kicks up quickly, or someone elevates the tempo quickly and repeatedly that guys like Voeckler suffer.