Everyone who's following is always "at their limit". Twelve guys are all strong enough to stay with the pace but not strong enough to do anything else? They're all absolutely identical strength? This is just a crutch used to let people off negative mindset racing. Louis Meintjes made a career out of having that perfect level of strength, not enough to do a turn but enough to respond to everything. It's just not realistic when the group gets that big. I can buy it if you're tailing a group of 3 or 4, but when you've got 10 to 12, or even like in stage 6, 40 guys all riding in the wheel just happy to be there, I'm not buying that each and every one of them is at their absolute limit and unable to do anything more.
A lot of people probably weren't at their limit but because Jumbo still had three men there, they didn't dare attack because they'd be pulled back by Kuss and then Roglič would still be fresh.
The other factor to consider there is that if everybody was at their absolute limit but not being dropped by the tempo Dumoulin was setting, then the tempo Dumoulin was setting wasn't enough to drop them, in which case expend him as a match, and let Kuss set the pace to get rid of some of them. Then Rogla has fewer people to think about. They'd still be outnumbering every other team in the group, but they'd be gaining more. It's even a steep mountain, so Kuss might even consider it worthwhile to ride! It's not like they can use the excuse they used to justify their timidness on stage 6 this time either, because today is a rest day.
We are headed deep into Giro 2012 territory as things stand, yes, but let's remember that the 2011 Tour only woke up from its stupor after the second rest day, and people somehow keep forgetting that the first two weeks of that were absolute dreck - everybody suddenly realised that basically they had a Dauphiné to compete for that would pay them a Tour de France maillot jaune, and went about racing it. Hopefully the same thing can happen this year. I'm not counting on it but the chances are still there.