Basically an engineered issue created by race management and course selection. In celebration of 100 years in the Alps, the two stages were designed to be exceedingly challenging and playground for the elite climbers, but with no thought to the impact upon nearly 40% of the peloton who's specialty is not high climbs. These riders are not chumps who don't belong at the TdF- they are slill some of the elite riders in the world. Only 55 riders finished stage 18 within 30 minutes of AS. The cutoff was set by rules at 33 minutes. +/- a few seconds. Riders like Rojas, Leipheimer, Voigt, Hincapie, Kreuziger, and Dean made it with less than 2 minutes to spare.
Greiple, Delage, Cancellara, Goss, Van Garderen, Petacchi, Millar, Martin, Flecha, Hushovd, LL Sanchez, Gilbert, Sabatini, Boasson Hagen, Swift, Farrar, Casar, Hinualt, Roy, Ventoso, and more finsihed in the pack with Cav at a little more than 2 min over. That basically wipes out the chances for the top 20 competing for the green jersey and even a couple of riders in the top 30's overall.
Want an excuse to reintroduce doping practices .... design and set expectations so that 40% of the most elite riders in the world fail because of a manufactured issue. That or take sprinting and non-climbing competitions out of the TdF and focus strictly on endurance and climbing. To anyone who says they should "just ride a little harder" ... pfft, yeah right. Those two stages and the way they were run were brutal and definitely separated the great from the good, but there was no chaff.