There's something about medium mountain stages that are up and down all day that makes people wet themselves even if the climbs are in all the wrong places and the stage in the wrong place in the race.
Even with the final 2km being steep, I think the Pog, Roglic and Bernal leave it all the way til the final 500m to attack here.
But it's not really in the wrong place in the race.
I mean, the GC guys are coming off 4 reasonably easy days (rest day, 10-12), and tomorrow is not a GC stage. Sure they have a decisive stage ahead on stage 15, but if you're one of the 10-15 guys at the top of the general classification and and feeling 'sensations', then imo it would be crazy not to try to take some reasonable time on at least some of your rivals on at least the final two climbs today.
Even if your projected form trajectory is to be continually improving (at least compared to your rivals), there is no guarantee that it will be a steady upward curve, and Bernal for example just might be feeling a little off on stage 15, so why hold back today, if he is feeling good?
And riders like Landa and Porte cannot waste any opportunities. Top 10 would be okay, but not greatly adding to their careers, and from where those guys are currently placed they still have quite a bit of work to do for a top 5, let along a podium. IF either of them are feeling good today, it would be crazy imo not to try something later on today. We are a full week on from stage 6. It should be a weaker peloton, and thus a greater chance for attackers to take advantage and a little time.